21890022 has 32 divisors (see below), whose sum is σ = 54584064. Its totient is φ = 5685600.

The previous prime is 21889993. The next prime is 21890047. The reversal of 21890022 is 22009812.

It is a junction number, because it is equal to n+sod(n) for n = 21889974 and 21890001.

It is a congruent number.

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, 23229 + ... + 24152.

It is an arithmetic number, because the mean of its divisors is an integer number (1705752).

Almost surely, 2^21890022 is an apocalyptic number.

21890022 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21890022 is an abundant number, since it is smaller than the sum of its proper divisors (32694042).

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

21890022 is a wasteful number, since it uses less digits than its factorization.

21890022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47404.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 21890022 is about 4678.6773772082. The cubic root of 21890022 is about 279.7362397108.

Adding to 21890022 its reverse (22009812), we get a palindrome (43899834).

The spelling of 21890022 in words is "twenty-one million, eight hundred ninety thousand, twenty-two".