21739446 has 24 divisors (see below), whose sum is σ = 47591544. Its totient is φ = 7171200.

The previous prime is 21739441. The next prime is 21739451. The reversal of 21739446 is 64493712.

It is an interprime number because it is at equal distance from previous prime (21739441) and next prime (21739451).

It is a self number, because there is not a number n which added to its sum of digits gives 21739446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21739441) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4480 + ... + 7971.

It is an arithmetic number, because the mean of its divisors is an integer number (1982981).

Almost surely, 2^21739446 is an apocalyptic number.

21739446 is an abundant number, since it is smaller than the sum of its proper divisors (25852098).

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

21739446 is a wasteful number, since it uses less digits than its factorization.

21739446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12556 (or 12553 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 21739446 is about 4662.5578816783. The cubic root of 21739446 is about 279.0933514265.

The spelling of 21739446 in words is "twenty-one million, seven hundred thirty-nine thousand, four hundred forty-six".