645993099 has 12 divisors (see below), whose sum is σ = 934109176. Its totient is φ = 430196832.

The previous prime is 645993091. The next prime is 645993113. The reversal of 645993099 is 990399546.

It is not a de Polignac number, because 645993099 - 2³ = 645993091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645993091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29869 + ... + 46734.

Almost surely, 2^645993099 is an apocalyptic number.

645993099 is a deficient number, since it is larger than the sum of its proper divisors (288116077).

645993099 is a wasteful number, since it uses less digits than its factorization.

645993099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77546 (or 77543 counting only the distinct ones).

The product of its (nonzero) digits is 2361960, while the sum is 54.

The square root of 645993099 is about 25416.3942958084. The cubic root of 645993099 is about 864.4554689242.

The spelling of 645993099 in words is "six hundred forty-five million, nine hundred ninety-three thousand, ninety-nine".