21477612 has 72 divisors (see below), whose sum is σ = 56351568. Its totient is φ = 6324480.

The previous prime is 21477611. The next prime is 21477623. The reversal of 21477612 is 21677412.

It is a super-2 number, since 2×21477612² = 922575634445088, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21477612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21477611) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 352062 + ... + 352122.

Almost surely, 2^21477612 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 21477612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28175784).

21477612 is an abundant number, since it is smaller than the sum of its proper divisors (34873956).

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

21477612 is a wasteful number, since it uses less digits than its factorization.

21477612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 116 counting only the distinct ones).

The product of its digits is 4704, while the sum is 30.

The square root of 21477612 is about 4634.3944588263. The cubic root of 21477612 is about 277.9683382674.

The spelling of 21477612 in words is "twenty-one million, four hundred seventy-seven thousand, six hundred twelve".