21516124 has 48 divisors (see below), whose sum is σ = 44513280. Its totient is φ = 8910720.

The previous prime is 21516119. The next prime is 21516127. The reversal of 21516124 is 42161512.

It is a junction number, because it is equal to n+sod(n) for n = 21516095 and 21516104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21516127) 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, 156984 + ... + 157120.

It is an arithmetic number, because the mean of its divisors is an integer number (927360).

Almost surely, 2^21516124 is an apocalyptic number.

It is an amenable number.

21516124 is an abundant number, since it is smaller than the sum of its proper divisors (22997156).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21516124 is a wasteful number, since it uses less digits than its factorization.

21516124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298 (or 296 counting only the distinct ones).

The product of its digits is 480, while the sum is 22.

The square root of 21516124 is about 4638.5476175199. The cubic root of 21516124 is about 278.1343828674.

Adding to 21516124 its reverse (42161512), we get a palindrome (63677636).

The spelling of 21516124 in words is "twenty-one million, five hundred sixteen thousand, one hundred twenty-four".