64644936987 has 8 divisors (see below), whose sum is σ = 86742251536. Its totient is φ = 42822123552.

The previous prime is 64644936947. The next prime is 64644936989. The reversal of 64644936987 is 78963944646.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 64644936987 - 2²⁶ = 64577828123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64644936989) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 68624728 + ... + 68625669.

It is an arithmetic number, because the mean of its divisors is an integer number (10842781442).

Almost surely, 2^64644936987 is an apocalyptic number.

64644936987 is a deficient number, since it is larger than the sum of its proper divisors (22097314549).

64644936987 is a wasteful number, since it uses less digits than its factorization.

64644936987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137250557.

The product of its digits is 188116992, while the sum is 66.

The spelling of 64644936987 in words is "sixty-four billion, six hundred forty-four million, nine hundred thirty-six thousand, nine hundred eighty-seven".