64040691 has 24 divisors (see below), whose sum is σ = 100875456. Its totient is φ = 35823840.

The previous prime is 64040663. The next prime is 64040693. The reversal of 64040691 is 19604046.

It is not a de Polignac number, because 64040691 - 2¹⁰ = 64039667 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (64040693) 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, 165 + ... + 11318.

It is an arithmetic number, because the mean of its divisors is an integer number (4203144).

Almost surely, 2^64040691 is an apocalyptic number.

64040691 is a deficient number, since it is larger than the sum of its proper divisors (36834765).

64040691 is a wasteful number, since it uses less digits than its factorization.

64040691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11523 (or 11510 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 64040691 is about 8002.5427833908. The cubic root of 64040691 is about 400.0847549569.

The spelling of 64040691 in words is "sixty-four million, forty thousand, six hundred ninety-one".