21704657742 has 12 divisors (see below), whose sum is σ = 47026758480. Its totient is φ = 7234885908.

The previous prime is 21704657731. The next prime is 21704657747. The reversal of 21704657742 is 24775640712.

21704657742 is a `hidden beast` number, since 2 + 1 + 70 + 4 + 6 + 577 + 4 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21704657747) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 602907142 + ... + 602907177.

It is an arithmetic number, because the mean of its divisors is an integer number (3918896540).

Almost surely, 2^21704657742 is an apocalyptic number.

21704657742 is an abundant number, since it is smaller than the sum of its proper divisors (25322100738).

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

21704657742 is a wasteful number, since it uses less digits than its factorization.

21704657742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1205814327 (or 1205814324 counting only the distinct ones).

The product of its (nonzero) digits is 658560, while the sum is 45.

The spelling of 21704657742 in words is "twenty-one billion, seven hundred four million, six hundred fifty-seven thousand, seven hundred forty-two".