21411990 has 24 divisors (see below), whose sum is σ = 55671408. Its totient is φ = 5709840.

The previous prime is 21411983. The next prime is 21412021. The reversal of 21411990 is 9911412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 118866 + ... + 119045.

It is an arithmetic number, because the mean of its divisors is an integer number (2319642).

Almost surely, 2^21411990 is an apocalyptic number.

21411990 is an abundant number, since it is smaller than the sum of its proper divisors (34259418).

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

21411990 is a wasteful number, since it uses less digits than its factorization.

21411990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237924 (or 237921 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 21411990 is about 4627.3091532769. The cubic root of 21411990 is about 277.6849509681.

The spelling of 21411990 in words is "twenty-one million, four hundred eleven thousand, nine hundred ninety".