647665451 has 2 divisors, whose sum is σ = 647665452. Its totient is φ = 647665450.

The previous prime is 647665433. The next prime is 647665457. The reversal of 647665451 is 154566746.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 647665451 - 2⁶ = 647665387 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (647665457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323832725 + 323832726.

It is an arithmetic number, because the mean of its divisors is an integer number (323832726).

Almost surely, 2^647665451 is an apocalyptic number.

647665451 is a deficient number, since it is larger than the sum of its proper divisors (1).

647665451 is an equidigital number, since it uses as much as digits as its factorization.

647665451 is an evil number, because the sum of its binary digits is even.

The product of its digits is 604800, while the sum is 44.

The square root of 647665451 is about 25449.2721113984. The cubic root of 647665451 is about 865.2007958231.

The spelling of 647665451 in words is "six hundred forty-seven million, six hundred sixty-five thousand, four hundred fifty-one".