21335522018 has 4 divisors (see below), whose sum is σ = 32003283030. Its totient is φ = 10667761008.

The previous prime is 21335522011. The next prime is 21335522029. The reversal of 21335522018 is 81022553312.

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., 19840694449 + 1494827569 = 140857^2 + 38663^2 .

It is not an unprimeable number, because it can be changed into a prime (21335522011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5333880503 + ... + 5333880506.

Almost surely, 2^21335522018 is an apocalyptic number.

21335522018 is a deficient number, since it is larger than the sum of its proper divisors (10667761012).

21335522018 is a wasteful number, since it uses less digits than its factorization.

21335522018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10667761011.

The product of its (nonzero) digits is 14400, while the sum is 32.

The spelling of 21335522018 in words is "twenty-one billion, three hundred thirty-five million, five hundred twenty-two thousand, eighteen".