15720973 has 2 divisors, whose sum is σ = 15720974. Its totient is φ = 15720972.

The previous prime is 15720959. The next prime is 15720979. The reversal of 15720973 is 37902751.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8311689 + 7409284 = 2883^2 + 2722^2 .

It is a cyclic number.

It is not a de Polignac number, because 15720973 - 2²¹ = 13623821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15720979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7860486 + 7860487.

It is an arithmetic number, because the mean of its divisors is an integer number (7860487).

Almost surely, 2^15720973 is an apocalyptic number.

It is an amenable number.

15720973 is a deficient number, since it is larger than the sum of its proper divisors (1).

15720973 is an equidigital number, since it uses as much as digits as its factorization.

15720973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13230, while the sum is 34.

The square root of 15720973 is about 3964.9682218146. The cubic root of 15720973 is about 250.5108115753.

The spelling of 15720973 in words is "fifteen million, seven hundred twenty thousand, nine hundred seventy-three".