21122964 has 48 divisors (see below), whose sum is σ = 55218240. Its totient is φ = 6982560.

The previous prime is 21122963. The next prime is 21122971. The reversal of 21122964 is 46922112.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122963) 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 15 ways as a sum of consecutive naturals, for example, 13402 + ... + 14894.

It is an arithmetic number, because the mean of its divisors is an integer number (1150380).

Almost surely, 2^21122964 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 21122964, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27609120).

21122964 is an abundant number, since it is smaller than the sum of its proper divisors (34095276).

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

21122964 is a wasteful number, since it uses less digits than its factorization.

21122964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1637 (or 1629 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 21122964 is about 4595.9725847746. The cubic root of 21122964 is about 276.4298594633.

The spelling of 21122964 in words is "twenty-one million, one hundred twenty-two thousand, nine hundred sixty-four".