21692387191 has 16 divisors (see below), whose sum is σ = 23668047360. Its totient is φ = 19813178880.

The previous prime is 21692387177. The next prime is 21692387201. The reversal of 21692387191 is 19178329612.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21692387191 - 2¹⁵ = 21692354423 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 (21692387131) 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, 121450 + ... + 241111.

It is an arithmetic number, because the mean of its divisors is an integer number (1479252960).

Almost surely, 2^21692387191 is an apocalyptic number.

21692387191 is a deficient number, since it is larger than the sum of its proper divisors (1975660169).

21692387191 is a wasteful number, since it uses less digits than its factorization.

21692387191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362694.

The product of its digits is 326592, while the sum is 49.

The spelling of 21692387191 in words is "twenty-one billion, six hundred ninety-two million, three hundred eighty-seven thousand, one hundred ninety-one".