645699699 has 6 divisors (see below), whose sum is σ = 932677356. Its totient is φ = 430466460.

The previous prime is 645699697. The next prime is 645699721. The reversal of 645699699 is 996996546.

645699699 is a `hidden beast` number, since 6 + 4 + 569 + 9 + 69 + 9 = 666.

It is not a de Polignac number, because 645699699 - 2¹ = 645699697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645699697) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35872197 + ... + 35872214.

It is an arithmetic number, because the mean of its divisors is an integer number (155446226).

Almost surely, 2^645699699 is an apocalyptic number.

645699699 is a deficient number, since it is larger than the sum of its proper divisors (286977657).

645699699 is a wasteful number, since it uses less digits than its factorization.

645699699 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71744417 (or 71744414 counting only the distinct ones).

The product of its digits is 28343520, while the sum is 63.

The square root of 645699699 is about 25410.6217751554. The cubic root of 645699699 is about 864.3245750374.

The spelling of 645699699 in words is "six hundred forty-five million, six hundred ninety-nine thousand, six hundred ninety-nine".