21214788 has 48 divisors (see below), whose sum is σ = 58404864. Its totient is φ = 5865120.

The previous prime is 21214777. The next prime is 21214847. The reversal of 21214788 is 88741212.

It is a happy number.

It is an unprimeable number.

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, 1470 + ... + 6677.

It is an arithmetic number, because the mean of its divisors is an integer number (1216768).

Almost surely, 2^21214788 is an apocalyptic number.

21214788 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21214788 is an abundant number, since it is smaller than the sum of its proper divisors (37190076).

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

21214788 is a wasteful number, since it uses less digits than its factorization.

21214788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8192 (or 8190 counting only the distinct ones).

The product of its digits is 7168, while the sum is 33.

The square root of 21214788 is about 4605.9513675244. The cubic root of 21214788 is about 276.8298381023.

The spelling of 21214788 in words is "twenty-one million, two hundred fourteen thousand, seven hundred eighty-eight".