21156450 has 48 divisors (see below), whose sum is σ = 59966400. Its totient is φ = 4835520.

The previous prime is 21156419. The next prime is 21156463. The reversal of 21156450 is 5465112.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21156450.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9025 + ... + 11124.

It is an arithmetic number, because the mean of its divisors is an integer number (1249300).

Almost surely, 2^21156450 is an apocalyptic number.

21156450 is an abundant number, since it is smaller than the sum of its proper divisors (38809950).

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

21156450 is a wasteful number, since it uses less digits than its factorization.

21156450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20171 (or 20166 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 21156450 is about 4599.6141142492. The cubic root of 21156450 is about 276.5758560692.

The spelling of 21156450 in words is "twenty-one million, one hundred fifty-six thousand, four hundred fifty".