21870222 has 16 divisors (see below), whose sum is σ = 47716992. Its totient is φ = 6627320.

The previous prime is 21870209. The next prime is 21870223. The reversal of 21870222 is 22207812.

It is a happy number.

It is a super-2 number, since 2×21870222² = 956613220658568, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21870192 and 21870201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21870223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 165618 + ... + 165749.

It is an arithmetic number, because the mean of its divisors is an integer number (2982312).

Almost surely, 2^21870222 is an apocalyptic number.

21870222 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21870222 is an abundant number, since it is smaller than the sum of its proper divisors (25846770).

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

21870222 is a wasteful number, since it uses less digits than its factorization.

21870222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331383.

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 21870222 is about 4676.5609158868. The cubic root of 21870222 is about 279.6518717681.

The spelling of 21870222 in words is "twenty-one million, eight hundred seventy thousand, two hundred twenty-two".