21219888 has 40 divisors (see below), whose sum is σ = 54983088. Its totient is φ = 7052032.

The previous prime is 21219883. The next prime is 21219901. The reversal of 21219888 is 88891212.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21219883) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31006 + ... + 31682.

Almost surely, 2^21219888 is an apocalyptic number.

It is an amenable number.

21219888 is an abundant number, since it is smaller than the sum of its proper divisors (33763200).

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

21219888 is a wasteful number, since it uses less digits than its factorization.

21219888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1341 (or 1335 counting only the distinct ones).

The product of its digits is 18432, while the sum is 39.

The square root of 21219888 is about 4606.5049658065. The cubic root of 21219888 is about 276.8520194703.

It can be divided in two parts, 212 and 19888, that added together give a triangular number (20100 = T₂₀₀).

The spelling of 21219888 in words is "twenty-one million, two hundred nineteen thousand, eight hundred eighty-eight".