15121881 has 12 divisors (see below), whose sum is σ = 21892260. Its totient is φ = 10058400.

The previous prime is 15121829. The next prime is 15121889. The reversal of 15121881 is 18812151.

It can be written as a sum of positive squares in 2 ways, for example, as 7750656 + 7371225 = 2784^2 + 2715^2 .

It is not a de Polignac number, because 15121881 - 2⁶ = 15121817 is a prime.

It is a super-2 number, since 2×15121881² = 457342569956322, which contains 22 as substring.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (15121889) 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, 2931 + ... + 6231.

It is an arithmetic number, because the mean of its divisors is an integer number (1824355).

Almost surely, 2^15121881 is an apocalyptic number.

It is an amenable number.

15121881 is a deficient number, since it is larger than the sum of its proper divisors (6770379).

15121881 is a wasteful number, since it uses less digits than its factorization.

15121881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3816 (or 3813 counting only the distinct ones).

The product of its digits is 640, while the sum is 27.

The square root of 15121881 is about 3888.6862820238. The cubic root of 15121881 is about 247.2873717137.

The spelling of 15121881 in words is "fifteen million, one hundred twenty-one thousand, eight hundred eighty-one".