15021997 has 2 divisors, whose sum is σ = 15021998. Its totient is φ = 15021996.

The previous prime is 15021961. The next prime is 15022009. The reversal of 15021997 is 79912051.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9400356 + 5621641 = 3066^2 + 2371^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15021997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15021197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7510998 + 7510999.

It is an arithmetic number, because the mean of its divisors is an integer number (7510999).

Almost surely, 2^15021997 is an apocalyptic number.

It is an amenable number.

15021997 is a deficient number, since it is larger than the sum of its proper divisors (1).

15021997 is an equidigital number, since it uses as much as digits as its factorization.

15021997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5670, while the sum is 34.

The square root of 15021997 is about 3875.8221063408. The cubic root of 15021997 is about 246.7417024782.

The spelling of 15021997 in words is "fifteen million, twenty-one thousand, nine hundred ninety-seven".