40644137 has 4 divisors (see below), whose sum is σ = 41200980. Its totient is φ = 40087296.

The previous prime is 40644133. The next prime is 40644139. The reversal of 40644137 is 73144604.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 25441936 + 15202201 = 5044^2 + 3899^2 .

It is a cyclic number.

It is not a de Polignac number, because 40644137 - 2² = 40644133 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40644133) 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, 278312 + ... + 278457.

It is an arithmetic number, because the mean of its divisors is an integer number (10300245).

Almost surely, 2^40644137 is an apocalyptic number.

It is an amenable number.

40644137 is a deficient number, since it is larger than the sum of its proper divisors (556843).

40644137 is an equidigital number, since it uses as much as digits as its factorization.

40644137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 556842.

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

The square root of 40644137 is about 6375.2754450298. The cubic root of 40644137 is about 343.8211871522.

The spelling of 40644137 in words is "forty million, six hundred forty-four thousand, one hundred thirty-seven".