21790632 has 64 divisors (see below), whose sum is σ = 57127680. Its totient is φ = 6918912.

The previous prime is 21790621. The next prime is 21790633. The reversal of 21790632 is 23609712.

It is a self number, because there is not a number n which added to its sum of digits gives 21790632.

It is not an unprimeable number, because it can be changed into a prime (21790633) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46833 + ... + 47295.

It is an arithmetic number, because the mean of its divisors is an integer number (892620).

Almost surely, 2^21790632 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 21790632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28563840).

21790632 is an abundant number, since it is smaller than the sum of its proper divisors (35337048).

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

21790632 is a wasteful number, since it uses less digits than its factorization.

21790632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 562 (or 558 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 21790632 is about 4668.0437015949. The cubic root of 21790632 is about 279.3122235319.

It can be divided in two parts, 21790 and 632, that added together give a palindrome (22422).

The spelling of 21790632 in words is "twenty-one million, seven hundred ninety thousand, six hundred thirty-two".