21557740268 has 6 divisors (see below), whose sum is σ = 37726045476. Its totient is φ = 10778870132.

The previous prime is 21557740261. The next prime is 21557740277. The reversal of 21557740268 is 86204775512.

It is not an unprimeable number, because it can be changed into a prime (21557740261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2694717530 + ... + 2694717537.

It is an arithmetic number, because the mean of its divisors is an integer number (6287674246).

Almost surely, 2^21557740268 is an apocalyptic number.

It is an amenable number.

21557740268 is a deficient number, since it is larger than the sum of its proper divisors (16168305208).

21557740268 is a wasteful number, since it uses less digits than its factorization.

21557740268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5389435071 (or 5389435069 counting only the distinct ones).

The product of its (nonzero) digits is 940800, while the sum is 47.

The spelling of 21557740268 in words is "twenty-one billion, five hundred fifty-seven million, seven hundred forty thousand, two hundred sixty-eight".