1640635451 has 16 divisors (see below), whose sum is σ = 2024374464. Its totient is φ = 1294786944.

The previous prime is 1640635441. The next prime is 1640635483. The reversal of 1640635451 is 1545360461.

It is a cyclic number.

It is not a de Polignac number, because 1640635451 - 2¹⁴ = 1640619067 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1640635421) 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, 13421 + ... + 58833.

It is an arithmetic number, because the mean of its divisors is an integer number (126523404).

Almost surely, 2^1640635451 is an apocalyptic number.

1640635451 is a deficient number, since it is larger than the sum of its proper divisors (383739013).

1640635451 is a wasteful number, since it uses less digits than its factorization.

1640635451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45830.

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 1640635451 is about 40504.7583747885. The cubic root of 1640635451 is about 1179.4259994355.

The spelling of 1640635451 in words is "one billion, six hundred forty million, six hundred thirty-five thousand, four hundred fifty-one".