64138220 has 12 divisors (see below), whose sum is σ = 134690304. Its totient is φ = 25655280.

The previous prime is 64138219. The next prime is 64138253. The reversal of 64138220 is 2283146.

It is a super-2 number, since 2×64138220² = 8227422529536800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 64138220.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1603436 + ... + 1603475.

It is an arithmetic number, because the mean of its divisors is an integer number (11224192).

Almost surely, 2^64138220 is an apocalyptic number.

It is an amenable number.

64138220 is an abundant number, since it is smaller than the sum of its proper divisors (70552084).

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

64138220 is a wasteful number, since it uses less digits than its factorization.

64138220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3206920 (or 3206918 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 64138220 is about 8008.6340907798. The cubic root of 64138220 is about 400.2877512817.

The spelling of 64138220 in words is "sixty-four million, one hundred thirty-eight thousand, two hundred twenty".