21725682 has 16 divisors (see below), whose sum is σ = 47401632. Its totient is φ = 6583520.

The previous prime is 21725663. The next prime is 21725689. The reversal of 21725682 is 28652712.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21725689) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 164523 + ... + 164654.

It is an arithmetic number, because the mean of its divisors is an integer number (2962602).

Almost surely, 2^21725682 is an apocalyptic number.

21725682 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21725682 is an abundant number, since it is smaller than the sum of its proper divisors (25675950).

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

21725682 is a wasteful number, since it uses less digits than its factorization.

21725682 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329193.

The product of its digits is 13440, while the sum is 33.

The square root of 21725682 is about 4661.0816341274. The cubic root of 21725682 is about 279.0344377526.

It can be divided in two parts, 2172568 and 2, that added together give a triangular number (2172570 = T₂₀₈₄).

The spelling of 21725682 in words is "twenty-one million, seven hundred twenty-five thousand, six hundred eighty-two".