21802428 has 36 divisors (see below), whose sum is σ = 55520920. Its totient is φ = 7213536.

The previous prime is 21802411. The next prime is 21802439. The reversal of 21802428 is 82420812.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2826 + ... + 7182.

Almost surely, 2^21802428 is an apocalyptic number.

It is an amenable number.

21802428 is an abundant number, since it is smaller than the sum of its proper divisors (33718492).

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

21802428 is a wasteful number, since it uses less digits than its factorization.

21802428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4506 (or 4501 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 21802428 is about 4669.3070149649. The cubic root of 21802428 is about 279.3626147986.

The spelling of 21802428 in words is "twenty-one million, eight hundred two thousand, four hundred twenty-eight".