21475916 has 48 divisors (see below), whose sum is σ = 47846400. Its totient is φ = 8361360.

The previous prime is 21475907. The next prime is 21475939. The reversal of 21475916 is 61957412.

It is a super-2 number, since 2×21475916² = 922429936078112, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14381 + ... + 15803.

It is an arithmetic number, because the mean of its divisors is an integer number (996800).

Almost surely, 2^21475916 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21475916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23923200).

21475916 is an abundant number, since it is smaller than the sum of its proper divisors (26370484).

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

21475916 is a wasteful number, since it uses less digits than its factorization.

21475916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1459 (or 1443 counting only the distinct ones).

The product of its digits is 15120, while the sum is 35.

The square root of 21475916 is about 4634.2114755371. The cubic root of 21475916 is about 277.9610213970.

The spelling of 21475916 in words is "twenty-one million, four hundred seventy-five thousand, nine hundred sixteen".