64720890 has 64 divisors (see below), whose sum is σ = 185875200. Its totient is φ = 15930432.

The previous prime is 64720871. The next prime is 64720913. The reversal of 64720890 is 9802746.

64720890 is a `hidden beast` number, since 647 + 2 + 0 + 8 + 9 + 0 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5710 + ... + 12729.

It is an arithmetic number, because the mean of its divisors is an integer number (2904300).

Almost surely, 2^64720890 is an apocalyptic number.

64720890 is an abundant number, since it is smaller than the sum of its proper divisors (121154310).

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

64720890 is a wasteful number, since it uses less digits than its factorization.

64720890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18468 (or 18462 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 64720890 is about 8044.9294589822. The cubic root of 64720890 is about 401.4962502758.

The spelling of 64720890 in words is "sixty-four million, seven hundred twenty thousand, eight hundred ninety".