21946512 has 160 divisors (see below), whose sum is σ = 69836800. Its totient is φ = 5927040.

The previous prime is 21946499. The next prime is 21946517. The reversal of 21946512 is 21564912.

It is a super-2 number, since 2×21946512² = 963298777932288, 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 21946512.

It is not an unprimeable number, because it can be changed into a prime (21946517) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 510363 + ... + 510405.

It is an arithmetic number, because the mean of its divisors is an integer number (436480).

Almost surely, 2^21946512 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 21946512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34918400).

21946512 is an abundant number, since it is smaller than the sum of its proper divisors (47890288).

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

21946512 is a wasteful number, since it uses less digits than its factorization.

21946512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106 (or 86 counting only the distinct ones).

The product of its digits is 4320, while the sum is 30.

The square root of 21946512 is about 4684.7104499638. The cubic root of 21946512 is about 279.9766647220.

The spelling of 21946512 in words is "twenty-one million, nine hundred forty-six thousand, five hundred twelve".