21358512 has 120 divisors (see below), whose sum is σ = 71386800. Its totient is φ = 6096384.

The previous prime is 21358501. The next prime is 21358537. The reversal of 21358512 is 21585312.

It is a happy number.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20664 + ... + 21672.

It is an arithmetic number, because the mean of its divisors is an integer number (594890).

Almost surely, 2^21358512 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 21358512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35693400).

21358512 is an abundant number, since it is smaller than the sum of its proper divisors (50028288).

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

21358512 is a wasteful number, since it uses less digits than its factorization.

21358512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1040 (or 1021 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 21358512 is about 4621.5270203689. The cubic root of 21358512 is about 277.4535787945.

The spelling of 21358512 in words is "twenty-one million, three hundred fifty-eight thousand, five hundred twelve".