64128987 has 24 divisors (see below), whose sum is σ = 102979968. Its totient is φ = 38188800.

The previous prime is 64128973. The next prime is 64128989. The reversal of 64128987 is 78982146.

It is not a de Polignac number, because 64128987 - 2⁷ = 64128859 is a prime.

It is a super-2 number, since 2×64128987² = 8225053947292338, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (64128989) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5214 + ... + 12467.

It is an arithmetic number, because the mean of its divisors is an integer number (4290832).

Almost surely, 2^64128987 is an apocalyptic number.

64128987 is a deficient number, since it is larger than the sum of its proper divisors (38850981).

64128987 is a wasteful number, since it uses less digits than its factorization.

64128987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17731 (or 17728 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 64128987 is about 8008.0576296628. The cubic root of 64128987 is about 400.2685425885.

The spelling of 64128987 in words is "sixty-four million, one hundred twenty-eight thousand, nine hundred eighty-seven".