64637790 has 64 divisors (see below), whose sum is σ = 183029760. Its totient is φ = 14296320.

The previous prime is 64637767. The next prime is 64637801. The reversal of 64637790 is 9773646.

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 1546 + ... + 11474.

It is an arithmetic number, because the mean of its divisors is an integer number (2859840).

Almost surely, 2^64637790 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64637790, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91514880).

64637790 is an abundant number, since it is smaller than the sum of its proper divisors (118391970).

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

64637790 is a wasteful number, since it uses less digits than its factorization.

64637790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9977.

The product of its (nonzero) digits is 190512, while the sum is 42.

The square root of 64637790 is about 8039.7630562101. The cubic root of 64637790 is about 401.3243396390.

The spelling of 64637790 in words is "sixty-four million, six hundred thirty-seven thousand, seven hundred ninety".