21128022 has 12 divisors (see below), whose sum is σ = 45777420. Its totient is φ = 7042668.

The previous prime is 21128017. The next prime is 21128027. The reversal of 21128022 is 22082112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21128017) and next prime (21128027).

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 1173779 = 21128022 / (2 + 1 + 1 + 2 + 8 + 0 + 2 + 2).

It is a junction number, because it is equal to n+sod(n) for n = 21127986 and 21128004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21128027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 586872 + ... + 586907.

It is an arithmetic number, because the mean of its divisors is an integer number (3814785).

Almost surely, 2^21128022 is an apocalyptic number.

21128022 is an abundant number, since it is smaller than the sum of its proper divisors (24649398).

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

21128022 is a wasteful number, since it uses less digits than its factorization.

21128022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1173787 (or 1173784 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 21128022 is about 4596.5228162166. The cubic root of 21128022 is about 276.4519218759.

The spelling of 21128022 in words is "twenty-one million, one hundred twenty-eight thousand, twenty-two".