64138356 has 18 divisors (see below), whose sum is σ = 162127602. Its totient is φ = 21379440.

The previous prime is 64138351. The next prime is 64138367. The reversal of 64138356 is 65383146.

64138356 is a `hidden beast` number, since 641 + 3 + 8 + 3 + 5 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 47196900 + 16941456 = 6870^2 + 4116^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×64138356² = 8227457420765472, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 1781621 = 64138356 / (6 + 4 + 1 + 3 + 8 + 3 + 5 + 6).

It is a self number, because there is not a number n which added to its sum of digits gives 64138356.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64138351) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 890775 + ... + 890846.

It is an arithmetic number, because the mean of its divisors is an integer number (9007089).

Almost surely, 2^64138356 is an apocalyptic number.

It is an amenable number.

64138356 is an abundant number, since it is smaller than the sum of its proper divisors (97989246).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64138356 is a wasteful number, since it uses less digits than its factorization.

64138356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1781631 (or 1781626 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 64138356 is about 8008.6425816114. The cubic root of 64138356 is about 400.2880342076.

The spelling of 64138356 in words is "sixty-four million, one hundred thirty-eight thousand, three hundred fifty-six".