64440137 has 4 divisors (see below), whose sum is σ = 64456320. Its totient is φ = 64423956.

The previous prime is 64440119. The next prime is 64440139. The reversal of 64440137 is 73104446.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 64440137 - 2²⁰ = 63391561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64440139) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2528 + ... + 11630.

It is an arithmetic number, because the mean of its divisors is an integer number (16114080).

Almost surely, 2^64440137 is an apocalyptic number.

It is an amenable number.

64440137 is a deficient number, since it is larger than the sum of its proper divisors (16183).

64440137 is an equidigital number, since it uses as much as digits as its factorization.

64440137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16182.

The product of its (nonzero) digits is 8064, while the sum is 29.

The square root of 64440137 is about 8027.4614293686. The cubic root of 64440137 is about 400.9148580749.

The spelling of 64440137 in words is "sixty-four million, four hundred forty thousand, one hundred thirty-seven".