15491971 has 16 divisors (see below), whose sum is σ = 17611776. Its totient is φ = 13500000.

The previous prime is 15491939. The next prime is 15492013. The reversal of 15491971 is 17919451.

15491971 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a 6-Lehmer number, since φ(15491971) divides (15491971-1)⁶.

It is a cyclic number.

It is not a de Polignac number, because 15491971 - 2⁵ = 15491939 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 15491971.

It is not an unprimeable number, because it can be changed into a prime (15491171) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61596 + ... + 61846.

It is an arithmetic number, because the mean of its divisors is an integer number (1100736).

Almost surely, 2^15491971 is an apocalyptic number.

15491971 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

15491971 is a deficient number, since it is larger than the sum of its proper divisors (2119805).

15491971 is a wasteful number, since it uses less digits than its factorization.

15491971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 474.

The product of its digits is 11340, while the sum is 37.

The square root of 15491971 is about 3935.9841209029. The cubic root of 15491971 is about 249.2884889291.

The spelling of 15491971 in words is "fifteen million, four hundred ninety-one thousand, nine hundred seventy-one".