21008293823 has 6 divisors (see below), whose sum is σ = 23091761112. Its totient is φ = 19098448820.

The previous prime is 21008293819. The next prime is 21008293841. The reversal of 21008293823 is 32839280012.

It is not a de Polignac number, because 21008293823 - 2² = 21008293819 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21008293123) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 86811011 + ... + 86811252.

It is an arithmetic number, because the mean of its divisors is an integer number (3848626852).

Almost surely, 2^21008293823 is an apocalyptic number.

21008293823 is a deficient number, since it is larger than the sum of its proper divisors (2083467289).

21008293823 is a wasteful number, since it uses less digits than its factorization.

21008293823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173622285 (or 173622274 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 38.

The spelling of 21008293823 in words is "twenty-one billion, eight million, two hundred ninety-three thousand, eight hundred twenty-three".