21533123534 has 16 divisors (see below), whose sum is σ = 34789230000. Its totient is φ = 9936949440.

The previous prime is 21533123519. The next prime is 21533123537. The reversal of 21533123534 is 43532133512.

It is a self number, because there is not a number n which added to its sum of digits gives 21533123534.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21533123537) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 139754 + ... + 250194.

It is an arithmetic number, because the mean of its divisors is an integer number (2174326875).

Almost surely, 2^21533123534 is an apocalyptic number.

21533123534 is a deficient number, since it is larger than the sum of its proper divisors (13256106466).

21533123534 is a wasteful number, since it uses less digits than its factorization.

21533123534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117955.

The product of its digits is 32400, while the sum is 32.

The spelling of 21533123534 in words is "twenty-one billion, five hundred thirty-three million, one hundred twenty-three thousand, five hundred thirty-four".