64631780 has 12 divisors (see below), whose sum is σ = 135726780. Its totient is φ = 25852704.

The previous prime is 64631767. The next prime is 64631813. The reversal of 64631780 is 8713646.

It can be written as a sum of positive squares in 2 ways, for example, as 10137856 + 54493924 = 3184^2 + 7382^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 64631780.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1615775 + ... + 1615814.

It is an arithmetic number, because the mean of its divisors is an integer number (11310565).

Almost surely, 2^64631780 is an apocalyptic number.

It is an amenable number.

64631780 is an abundant number, since it is smaller than the sum of its proper divisors (71095000).

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

64631780 is a wasteful number, since it uses less digits than its factorization.

64631780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3231598 (or 3231596 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 64631780 is about 8039.3892802874. The cubic root of 64631780 is about 401.3119009193.

The spelling of 64631780 in words is "sixty-four million, six hundred thirty-one thousand, seven hundred eighty".