21122860 has 24 divisors (see below), whose sum is σ = 48391056. Its totient is φ = 7680960.

The previous prime is 21122821. The next prime is 21122863. The reversal of 21122860 is 6822112.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (21122863) 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 7 ways as a sum of consecutive naturals, for example, 47787 + ... + 48226.

It is an arithmetic number, because the mean of its divisors is an integer number (2016294).

Almost surely, 2^21122860 is an apocalyptic number.

21122860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21122860 is an abundant number, since it is smaller than the sum of its proper divisors (27268196).

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

21122860 is a wasteful number, since it uses less digits than its factorization.

21122860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96033 (or 96031 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 21122860 is about 4595.9612705070. The cubic root of 21122860 is about 276.4294057903.

Adding to 21122860 its reverse (6822112), we get a palindrome (27944972).

The spelling of 21122860 in words is "twenty-one million, one hundred twenty-two thousand, eight hundred sixty".