645515407 has 2 divisors, whose sum is σ = 645515408. Its totient is φ = 645515406.

The previous prime is 645515383. The next prime is 645515413. The reversal of 645515407 is 704515546.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645515407 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645515467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322757703 + 322757704.

It is an arithmetic number, because the mean of its divisors is an integer number (322757704).

Almost surely, 2^645515407 is an apocalyptic number.

645515407 is a deficient number, since it is larger than the sum of its proper divisors (1).

645515407 is an equidigital number, since it uses as much as digits as its factorization.

645515407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84000, while the sum is 37.

The square root of 645515407 is about 25406.9952375325. The cubic root of 645515407 is about 864.2423369828.

The spelling of 645515407 in words is "six hundred forty-five million, five hundred fifteen thousand, four hundred seven".