645769399 has 16 divisors (see below), whose sum is σ = 740361600. Its totient is φ = 557897760.

The previous prime is 645769391. The next prime is 645769441. The reversal of 645769399 is 993967546.

It is a cyclic number.

It is not a de Polignac number, because 645769399 - 2³ = 645769391 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645769391) 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, 949 + ... + 35950.

It is an arithmetic number, because the mean of its divisors is an integer number (46272600).

Almost surely, 2^645769399 is an apocalyptic number.

645769399 is a deficient number, since it is larger than the sum of its proper divisors (94592201).

645769399 is a wasteful number, since it uses less digits than its factorization.

645769399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36990.

The product of its digits is 11022480, while the sum is 58.

The square root of 645769399 is about 25411.9932118675. The cubic root of 645769399 is about 864.3556737331.

The spelling of 645769399 in words is "six hundred forty-five million, seven hundred sixty-nine thousand, three hundred ninety-nine".