21020292 has 72 divisors (see below), whose sum is σ = 55991936. Its totient is φ = 6640704.

The previous prime is 21020281. The next prime is 21020299. The reversal of 21020292 is 29202012.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21020299) 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, 57093 + ... + 57459.

Almost surely, 2^21020292 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21020292, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27995968).

21020292 is an abundant number, since it is smaller than the sum of its proper divisors (34971644).

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

21020292 is a wasteful number, since it uses less digits than its factorization.

21020292 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 457 (or 452 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 21020292 is about 4584.7891990799. The cubic root of 21020292 is about 275.9812526649.

It can be divided in two parts, 21020 and 292, that added together give a palindrome (21312).

The spelling of 21020292 in words is "twenty-one million, twenty thousand, two hundred ninety-two".