21801892 has 48 divisors (see below), whose sum is σ = 46448640. Its totient is φ = 8746272.

The previous prime is 21801887. The next prime is 21801893. The reversal of 21801892 is 29810812.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21801893) 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, 56733 + ... + 57115.

It is an arithmetic number, because the mean of its divisors is an integer number (967680).

Almost surely, 2^21801892 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 21801892, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23224320).

21801892 is an abundant number, since it is smaller than the sum of its proper divisors (24646748).

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

21801892 is a wasteful number, since it uses less digits than its factorization.

21801892 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520 (or 518 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 21801892 is about 4669.2496185147. The cubic root of 21801892 is about 279.3603254574.

The spelling of 21801892 in words is "twenty-one million, eight hundred one thousand, eight hundred ninety-two".