15720497 has 4 divisors (see below), whose sum is σ = 16929780. Its totient is φ = 14511216.

The previous prime is 15720487. The next prime is 15720511. The reversal of 15720497 is 79402751.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79402751 = 827 ⋅96013.

It can be written as a sum of positive squares in 2 ways, for example, as 1852321 + 13868176 = 1361^2 + 3724^2 .

It is a cyclic number.

It is not a de Polignac number, because 15720497 - 2¹⁴ = 15704113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15720437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 604622 + ... + 604647.

It is an arithmetic number, because the mean of its divisors is an integer number (4232445).

Almost surely, 2^15720497 is an apocalyptic number.

It is an amenable number.

15720497 is a deficient number, since it is larger than the sum of its proper divisors (1209283).

15720497 is a wasteful number, since it uses less digits than its factorization.

15720497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1209282.

The product of its (nonzero) digits is 17640, while the sum is 35.

The square root of 15720497 is about 3964.9081956585. The cubic root of 15720497 is about 250.5082832256.

The spelling of 15720497 in words is "fifteen million, seven hundred twenty thousand, four hundred ninety-seven".