625459721 has 2 divisors, whose sum is σ = 625459722. Its totient is φ = 625459720.

The previous prime is 625459717. The next prime is 625459741. The reversal of 625459721 is 127954526.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 551310400 + 74149321 = 23480^2 + 8611^2 .

It is a cyclic number.

It is not a de Polignac number, because 625459721 - 2² = 625459717 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (625459741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 312729860 + 312729861.

It is an arithmetic number, because the mean of its divisors is an integer number (312729861).

Almost surely, 2^625459721 is an apocalyptic number.

It is an amenable number.

625459721 is a deficient number, since it is larger than the sum of its proper divisors (1).

625459721 is an equidigital number, since it uses as much as digits as its factorization.

625459721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 151200, while the sum is 41.

The square root of 625459721 is about 25009.1927298743. The cubic root of 625459721 is about 855.1975517886.

The spelling of 625459721 in words is "six hundred twenty-five million, four hundred fifty-nine thousand, seven hundred twenty-one".