64644870 has 16 divisors (see below), whose sum is σ = 155147760. Its totient is φ = 17238624.

The previous prime is 64644851. The next prime is 64644871. The reversal of 64644870 is 7844646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64644871) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1077385 + ... + 1077444.

It is an arithmetic number, because the mean of its divisors is an integer number (9696735).

Almost surely, 2^64644870 is an apocalyptic number.

64644870 is an abundant number, since it is smaller than the sum of its proper divisors (90502890).

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

64644870 is a wasteful number, since it uses less digits than its factorization.

64644870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2154839.

The product of its (nonzero) digits is 129024, while the sum is 39.

The square root of 64644870 is about 8040.2033556372. The cubic root of 64644870 is about 401.3389919169.

The spelling of 64644870 in words is "sixty-four million, six hundred forty-four thousand, eight hundred seventy".