21739692 has 96 divisors (see below), whose sum is σ = 58480128. Its totient is φ = 6234624.

The previous prime is 21739687. The next prime is 21739693. The reversal of 21739692 is 29693712.

It is a super-2 number, since 2×21739692² = 945228416509728, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 21739692.

It is not an unprimeable number, because it can be changed into a prime (21739693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 261883 + ... + 261965.

It is an arithmetic number, because the mean of its divisors is an integer number (609168).

Almost surely, 2^21739692 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 21739692, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29240064).

21739692 is an abundant number, since it is smaller than the sum of its proper divisors (36740436).

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

21739692 is a wasteful number, since it uses less digits than its factorization.

21739692 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199 (or 197 counting only the distinct ones).

The product of its digits is 40824, while the sum is 39.

The square root of 21739692 is about 4662.5842619732. The cubic root of 21739692 is about 279.0944041473.

The spelling of 21739692 in words is "twenty-one million, seven hundred thirty-nine thousand, six hundred ninety-two".