64905381 has 10 divisors (see below), whose sum is σ = 96957542. Its totient is φ = 43270200.

The previous prime is 64905377. The next prime is 64905457. The reversal of 64905381 is 18350946.

64905381 is a `hidden beast` number, since 649 + 0 + 5 + 3 + 8 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 55264356 + 9641025 = 7434^2 + 3105^2 .

It is not a de Polignac number, because 64905381 - 2² = 64905377 is a prime.

It is a super-2 number, since 2×64905381² = 8425416965510322, 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 (64905331) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 400570 + ... + 400731.

Almost surely, 2^64905381 is an apocalyptic number.

It is an amenable number.

64905381 is a deficient number, since it is larger than the sum of its proper divisors (32052161).

64905381 is an equidigital number, since it uses as much as digits as its factorization.

64905381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 801313 (or 801304 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 64905381 is about 8056.3875899810. The cubic root of 64905381 is about 401.8773851934.

The spelling of 64905381 in words is "sixty-four million, nine hundred five thousand, three hundred eighty-one".