64147381 has 4 divisors (see below), whose sum is σ = 65881132. Its totient is φ = 62413632.

The previous prime is 64147351. The next prime is 64147387. The reversal of 64147381 is 18374146.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 51122500 + 13024881 = 7150^2 + 3609^2 .

It is a cyclic number.

It is not a de Polignac number, because 64147381 - 2¹⁵ = 64114613 is a prime.

It is a super-2 number, since 2×64147381² = 8229772978318322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64147387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 866820 + ... + 866893.

It is an arithmetic number, because the mean of its divisors is an integer number (16470283).

Almost surely, 2^64147381 is an apocalyptic number.

It is an amenable number.

64147381 is a deficient number, since it is larger than the sum of its proper divisors (1733751).

64147381 is a wasteful number, since it uses less digits than its factorization.

64147381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1733750.

The product of its digits is 16128, while the sum is 34.

The square root of 64147381 is about 8009.2060155798. The cubic root of 64147381 is about 400.3068083614.

The spelling of 64147381 in words is "sixty-four million, one hundred forty-seven thousand, three hundred eighty-one".