21704742 has 12 divisors (see below), whose sum is σ = 47026980. Its totient is φ = 7234908.

The previous prime is 21704737. The next prime is 21704791. The reversal of 21704742 is 24740712.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 602892 + ... + 602927.

It is an arithmetic number, because the mean of its divisors is an integer number (3918915).

Almost surely, 2^21704742 is an apocalyptic number.

21704742 is an abundant number, since it is smaller than the sum of its proper divisors (25322238).

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

21704742 is a wasteful number, since it uses less digits than its factorization.

21704742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1205827 (or 1205824 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 27.

The square root of 21704742 is about 4658.8348328740. The cubic root of 21704742 is about 278.9447610993.

The spelling of 21704742 in words is "twenty-one million, seven hundred four thousand, seven hundred forty-two".