15506997 has 12 divisors (see below), whose sum is σ = 22727040. Its totient is φ = 9397960.

The previous prime is 15506977. The next prime is 15507001. The reversal of 15506997 is 79960551.

It is not a de Polignac number, because 15506997 - 2⁸ = 15506741 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15506927) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20997 + ... + 21722.

It is an arithmetic number, because the mean of its divisors is an integer number (1893920).

Almost surely, 2^15506997 is an apocalyptic number.

It is an amenable number.

15506997 is a deficient number, since it is larger than the sum of its proper divisors (7220043).

15506997 is a wasteful number, since it uses less digits than its factorization.

15506997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42744 (or 42733 counting only the distinct ones).

The product of its (nonzero) digits is 85050, while the sum is 42.

The square root of 15506997 is about 3937.8924566321. The cubic root of 15506997 is about 249.3690596634.

The spelling of 15506997 in words is "fifteen million, five hundred six thousand, nine hundred ninety-seven".