15630991 has 4 divisors (see below), whose sum is σ = 15647184. Its totient is φ = 15614800.

The previous prime is 15630949. The next prime is 15631001. The reversal of 15630991 is 19903651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19903651 = 17 ⋅1170803.

It is a cyclic number.

It is not a de Polignac number, because 15630991 - 2¹⁵ = 15598223 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15630911) 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, 6550 + ... + 8611.

It is an arithmetic number, because the mean of its divisors is an integer number (3911796).

Almost surely, 2^15630991 is an apocalyptic number.

15630991 is a deficient number, since it is larger than the sum of its proper divisors (16193).

15630991 is a wasteful number, since it uses less digits than its factorization.

15630991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16192.

The product of its (nonzero) digits is 7290, while the sum is 34.

The square root of 15630991 is about 3953.6048108024. The cubic root of 15630991 is about 250.0319479171.

The spelling of 15630991 in words is "fifteen million, six hundred thirty thousand, nine hundred ninety-one".