64391020 has 48 divisors (see below), whose sum is σ = 142057440. Its totient is φ = 24482304.

The previous prime is 64391017. The next prime is 64391039. The reversal of 64391020 is 2019346.

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, 38032 + ... + 39688.

It is an arithmetic number, because the mean of its divisors is an integer number (2959530).

Almost surely, 2^64391020 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 64391020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71028720).

64391020 is an abundant number, since it is smaller than the sum of its proper divisors (77666420).

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

64391020 is a wasteful number, since it uses less digits than its factorization.

64391020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1762 (or 1760 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 64391020 is about 8024.4015353171. The cubic root of 64391020 is about 400.8129715737.

The spelling of 64391020 in words is "sixty-four million, three hundred ninety-one thousand, twenty".