64128537 has 16 divisors (see below), whose sum is σ = 103642560. Its totient is φ = 38865600.

The previous prime is 64128509. The next prime is 64128563. The reversal of 64128537 is 73582146.

64128537 is a `hidden beast` number, since 641 + 2 + 8 + 5 + 3 + 7 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-64128537 is a prime.

It is a super-2 number, since 2×64128537² = 8224938515520738, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (64128587) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 107664 + ... + 108257.

It is an arithmetic number, because the mean of its divisors is an integer number (6477660).

Almost surely, 2^64128537 is an apocalyptic number.

It is an amenable number.

64128537 is a deficient number, since it is larger than the sum of its proper divisors (39514023).

64128537 is a wasteful number, since it uses less digits than its factorization.

64128537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215941 (or 215935 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 64128537 is about 8008.0295329126. The cubic root of 64128537 is about 400.2676063439.

The spelling of 64128537 in words is "sixty-four million, one hundred twenty-eight thousand, five hundred thirty-seven".