21395589634 has 4 divisors (see below), whose sum is σ = 32093384454. Its totient is φ = 10697794816.

The previous prime is 21395589629. The next prime is 21395589701. The reversal of 21395589634 is 43698559312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18784073025 + 2611516609 = 137055^2 + 51103^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5348897407 + ... + 5348897410.

Almost surely, 2^21395589634 is an apocalyptic number.

21395589634 is a deficient number, since it is larger than the sum of its proper divisors (10697794820).

21395589634 is a wasteful number, since it uses less digits than its factorization.

21395589634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10697794819.

The product of its digits is 6998400, while the sum is 55.

The spelling of 21395589634 in words is "twenty-one billion, three hundred ninety-five million, five hundred eighty-nine thousand, six hundred thirty-four".