21523914 has 16 divisors (see below), whose sum is σ = 47831040. Its totient is φ = 7174620.

The previous prime is 21523907. The next prime is 21523927. The reversal of 21523914 is 41932512.

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

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, 199242 + ... + 199349.

It is an arithmetic number, because the mean of its divisors is an integer number (2989440).

Almost surely, 2^21523914 is an apocalyptic number.

21523914 is an abundant number, since it is smaller than the sum of its proper divisors (26307126).

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

21523914 is a wasteful number, since it uses less digits than its factorization.

21523914 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398602 (or 398596 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 21523914 is about 4639.3872440226. The cubic root of 21523914 is about 278.1679453779.

The spelling of 21523914 in words is "twenty-one million, five hundred twenty-three thousand, nine hundred fourteen".