21173506323 has 16 divisors (see below), whose sum is σ = 29146291200. Its totient is φ = 13658329440.

The previous prime is 21173506283. The next prime is 21173506363. The reversal of 21173506323 is 32360537112.

It is an interprime number because it is at equal distance from previous prime (21173506283) and next prime (21173506363).

It is not a de Polignac number, because 21173506323 - 2¹⁰ = 21173505299 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21173506363) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 882733 + ... + 906401.

It is an arithmetic number, because the mean of its divisors is an integer number (1821643200).

Almost surely, 2^21173506323 is an apocalyptic number.

21173506323 is a deficient number, since it is larger than the sum of its proper divisors (7972784877).

21173506323 is a wasteful number, since it uses less digits than its factorization.

21173506323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33322.

The product of its (nonzero) digits is 22680, while the sum is 33.

The spelling of 21173506323 in words is "twenty-one billion, one hundred seventy-three million, five hundred six thousand, three hundred twenty-three".