21892420 has 48 divisors (see below), whose sum is σ = 50512896. Its totient is φ = 7904000.

The previous prime is 21892411. The next prime is 21892441. The reversal of 21892420 is 2429812.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41760 + ... + 42280.

It is an arithmetic number, because the mean of its divisors is an integer number (1052352).

Almost surely, 2^21892420 is an apocalyptic number.

21892420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21892420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25256448).

21892420 is an abundant number, since it is smaller than the sum of its proper divisors (28620476).

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

21892420 is a wasteful number, since it uses less digits than its factorization.

21892420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 732 (or 730 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 21892420 is about 4678.9336391960. The cubic root of 21892420 is about 279.7464541517.

The spelling of 21892420 in words is "twenty-one million, eight hundred ninety-two thousand, four hundred twenty".