1640635331 has 2 divisors, whose sum is σ = 1640635332. Its totient is φ = 1640635330.

The previous prime is 1640635327. The next prime is 1640635349. The reversal of 1640635331 is 1335360461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1640635331 - 2² = 1640635327 is a prime.

It is a super-2 number, since 2×1640635331² = 5383368578650959122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1640635391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820317665 + 820317666.

It is an arithmetic number, because the mean of its divisors is an integer number (820317666).

Almost surely, 2^1640635331 is an apocalyptic number.

1640635331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640635331 is an equidigital number, since it uses as much as digits as its factorization.

1640635331 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 32.

The square root of 1640635331 is about 40504.7568934810. The cubic root of 1640635331 is about 1179.4259706801.

Adding to 1640635331 its reverse (1335360461), we get a palindrome (2975995792).

The spelling of 1640635331 in words is "one billion, six hundred forty million, six hundred thirty-five thousand, three hundred thirty-one".