21419988 has 24 divisors (see below), whose sum is σ = 50090208. Its totient is φ = 7124256.

The previous prime is 21419939. The next prime is 21420001. The reversal of 21419988 is 88991412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4570 + ... + 7982.

It is an arithmetic number, because the mean of its divisors is an integer number (2087092).

Almost surely, 2^21419988 is an apocalyptic number.

It is an amenable number.

21419988 is an abundant number, since it is smaller than the sum of its proper divisors (28670220).

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

21419988 is a wasteful number, since it uses less digits than its factorization.

21419988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3943 (or 3941 counting only the distinct ones).

The product of its digits is 41472, while the sum is 42.

The square root of 21419988 is about 4628.1732897548. The cubic root of 21419988 is about 277.7195211282.

It can be divided in two parts, 214 and 19988, that added together give a palindrome (20202).

The spelling of 21419988 in words is "twenty-one million, four hundred nineteen thousand, nine hundred eighty-eight".