21927987393 has 8 divisors (see below), whose sum is σ = 31486340928. Its totient is φ = 13494146064.

The previous prime is 21927987371. The next prime is 21927987407. The reversal of 21927987393 is 39378972912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21927987393 - 2⁶ = 21927987329 is a prime.

It is a super-2 number, since 2×21927987393² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21927987593) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 281128005 + ... + 281128082.

It is an arithmetic number, because the mean of its divisors is an integer number (3935792616).

Almost surely, 2^21927987393 is an apocalyptic number.

It is an amenable number.

21927987393 is a deficient number, since it is larger than the sum of its proper divisors (9558353535).

21927987393 is a wasteful number, since it uses less digits than its factorization.

21927987393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 562256103.

The product of its digits is 10287648, while the sum is 60.

The spelling of 21927987393 in words is "twenty-one billion, nine hundred twenty-seven million, nine hundred eighty-seven thousand, three hundred ninety-three".