21698285823 has 12 divisors (see below), whose sum is σ = 31343265408. Its totient is φ = 14464925280.

The previous prime is 21698285797. The next prime is 21698285827. The reversal of 21698285823 is 32858289612.

It is a happy number.

It is not a de Polignac number, because 21698285823 - 2¹⁶ = 21698220287 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21698285823.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21698285827) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 340386 + ... + 399072.

It is an arithmetic number, because the mean of its divisors is an integer number (2611938784).

Almost surely, 2^21698285823 is an apocalyptic number.

21698285823 is a deficient number, since it is larger than the sum of its proper divisors (9644979585).

21698285823 is a wasteful number, since it uses less digits than its factorization.

21698285823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99774 (or 99771 counting only the distinct ones).

The product of its digits is 3317760, while the sum is 54.

The spelling of 21698285823 in words is "twenty-one billion, six hundred ninety-eight million, two hundred eighty-five thousand, eight hundred twenty-three".