15720457 has 2 divisors, whose sum is σ = 15720458. Its totient is φ = 15720456.

The previous prime is 15720451. The next prime is 15720469. The reversal of 15720457 is 75402751.

15720457 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10169721 + 5550736 = 3189^2 + 2356^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15720457 is a prime.

It is a plaindrome in base 13.

It is not a weakly prime, because it can be changed into another prime (15720451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7860228 + 7860229.

It is an arithmetic number, because the mean of its divisors is an integer number (7860229).

Almost surely, 2^15720457 is an apocalyptic number.

It is an amenable number.

15720457 is a deficient number, since it is larger than the sum of its proper divisors (1).

15720457 is an equidigital number, since it uses as much as digits as its factorization.

15720457 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9800, while the sum is 31.

The square root of 15720457 is about 3964.9031514023. The cubic root of 15720457 is about 250.5080707570.

The spelling of 15720457 in words is "fifteen million, seven hundred twenty thousand, four hundred fifty-seven".