21117071423 has 16 divisors (see below), whose sum is σ = 24566051136. Its totient is φ = 17778216960.

The previous prime is 21117071389. The next prime is 21117071429. The reversal of 21117071423 is 32417071112.

It is a de Polignac number, because none of the positive numbers 2^k-21117071423 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 (21117071429) 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, 37415 + ... + 208887.

It is an arithmetic number, because the mean of its divisors is an integer number (1535378196).

Almost surely, 2^21117071423 is an apocalyptic number.

21117071423 is a deficient number, since it is larger than the sum of its proper divisors (3448979713).

21117071423 is a wasteful number, since it uses less digits than its factorization.

21117071423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171794.

The product of its (nonzero) digits is 2352, while the sum is 29.

The spelling of 21117071423 in words is "twenty-one billion, one hundred seventeen million, seventy-one thousand, four hundred twenty-three".