21769872 has 40 divisors (see below), whose sum is σ = 56960640. Its totient is φ = 7163520.

The previous prime is 21769861. The next prime is 21769903. The reversal of 21769872 is 27896712.

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, 922 + ... + 6662.

It is an arithmetic number, because the mean of its divisors is an integer number (1424016).

Almost surely, 2^21769872 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 21769872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28480320).

21769872 is an abundant number, since it is smaller than the sum of its proper divisors (35190768).

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

21769872 is a wasteful number, since it uses less digits than its factorization.

21769872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5831 (or 5825 counting only the distinct ones).

The product of its digits is 84672, while the sum is 42.

The square root of 21769872 is about 4665.8195421598. The cubic root of 21769872 is about 279.2234948195.

The spelling of 21769872 in words is "twenty-one million, seven hundred sixty-nine thousand, eight hundred seventy-two".