64121904 has 120 divisors (see below), whose sum is σ = 223771392. Its totient is φ = 16652160.

The previous prime is 64121879. The next prime is 64121957. The reversal of 64121904 is 40912146.

64121904 is a `hidden beast` number, since 641 + 2 + 19 + 0 + 4 = 666.

It is a super-2 number, since 2×64121904² = 8223237145170432, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8197 + ... + 13979.

Almost surely, 2^64121904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64121904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111885696).

64121904 is an abundant number, since it is smaller than the sum of its proper divisors (159649488).

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

64121904 is a wasteful number, since it uses less digits than its factorization.

64121904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5815 (or 5806 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 64121904 is about 8007.6153753786. The cubic root of 64121904 is about 400.2538055894.

It can be divided in two parts, 64121 and 904, that added together give a square (65025 = 255²).

The spelling of 64121904 in words is "sixty-four million, one hundred twenty-one thousand, nine hundred four".