21518152 has 16 divisors (see below), whose sum is σ = 40448700. Its totient is φ = 10731840.

The previous prime is 21518143. The next prime is 21518197. The reversal of 21518152 is 25181512.

It can be written as a sum of positive squares in 2 ways, for example, as 12068676 + 9449476 = 3474^2 + 3074^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 174 + ... + 6562.

Almost surely, 2^21518152 is an apocalyptic number.

It is an amenable number.

21518152 is a deficient number, since it is larger than the sum of its proper divisors (18930548).

21518152 is a wasteful number, since it uses less digits than its factorization.

21518152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6816 (or 6812 counting only the distinct ones).

The product of its digits is 800, while the sum is 25.

The square root of 21518152 is about 4638.7662152775. The cubic root of 21518152 is about 278.1431211018.

Adding to 21518152 its reverse (25181512), we get a palindrome (46699664).

The spelling of 21518152 in words is "twenty-one million, five hundred eighteen thousand, one hundred fifty-two".