15521481 has 24 divisors (see below), whose sum is σ = 23587200. Its totient is φ = 9816576.

The previous prime is 15521477. The next prime is 15521497. The reversal of 15521481 is 18412551.

It is not a de Polignac number, because 15521481 - 2² = 15521477 is a prime.

It is a super-2 number, since 2×15521481² = 481832744866722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (15521431) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34345 + ... + 34793.

It is an arithmetic number, because the mean of its divisors is an integer number (982800).

Almost surely, 2^15521481 is an apocalyptic number.

It is an amenable number.

15521481 is a deficient number, since it is larger than the sum of its proper divisors (8065719).

15521481 is a wasteful number, since it uses less digits than its factorization.

15521481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645 (or 642 counting only the distinct ones).

The product of its digits is 1600, while the sum is 27.

The square root of 15521481 is about 3939.7310821933. The cubic root of 15521481 is about 249.4466748955.

The spelling of 15521481 in words is "fifteen million, five hundred twenty-one thousand, four hundred eighty-one".