21534680668 has 12 divisors (see below), whose sum is σ = 37788379552. Its totient is φ = 10738000800.

The previous prime is 21534680653. The next prime is 21534680669. The reversal of 21534680668 is 86608643512.

It is a happy number.

It is a hoax number, since the sum of its digits (49) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21534680669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7333233 + ... + 7336168.

Almost surely, 2^21534680668 is an apocalyptic number.

It is an amenable number.

21534680668 is a deficient number, since it is larger than the sum of its proper divisors (16253698884).

21534680668 is a wasteful number, since it uses less digits than its factorization.

21534680668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14669772 (or 14669770 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 49.

The spelling of 21534680668 in words is "twenty-one billion, five hundred thirty-four million, six hundred eighty thousand, six hundred sixty-eight".