64839040 has 128 divisors (see below), whose sum is σ = 181984320. Its totient is φ = 21626880.

The previous prime is 64839031. The next prime is 64839067. The reversal of 64839040 is 4093846.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×64839040² = 8408202216243200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 64838987 and 64839005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 183504 + ... + 183856.

Almost surely, 2^64839040 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 64839040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90992160).

64839040 is an abundant number, since it is smaller than the sum of its proper divisors (117145280).

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

64839040 is a wasteful number, since it uses less digits than its factorization.

64839040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420 (or 408 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 64839040 is about 8052.2692453743. The cubic root of 64839040 is about 401.7404163940.

The spelling of 64839040 in words is "sixty-four million, eight hundred thirty-nine thousand, forty".