64905840 has 160 divisors (see below), whose sum is σ = 226176000. Its totient is φ = 17107200.

The previous prime is 64905823. The next prime is 64905853. The reversal of 64905840 is 4850946.

64905840 is a `hidden beast` number, since 649 + 0 + 5 + 8 + 4 + 0 = 666.

It is a super-2 number, since 2×64905840² = 8425536132211200, which contains 22 as substring.

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

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 64905795 and 64905804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 326061 + ... + 326259.

It is an arithmetic number, because the mean of its divisors is an integer number (1413600).

Almost surely, 2^64905840 is an apocalyptic number.

64905840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64905840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113088000).

64905840 is an abundant number, since it is smaller than the sum of its proper divisors (161270160).

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

64905840 is a wasteful number, since it uses less digits than its factorization.

64905840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372 (or 360 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 64905840 is about 8056.4160766435. The cubic root of 64905840 is about 401.8783325277.

The spelling of 64905840 in words is "sixty-four million, nine hundred five thousand, eight hundred forty".