21909363993 has 24 divisors (see below), whose sum is σ = 34530184416. Its totient is φ = 13275964800.

The previous prime is 21909363953. The next prime is 21909364033. The reversal of 21909363993 is 39936390912.

It is a happy number.

21909363993 is a `hidden beast` number, since 2 + 190 + 9 + 363 + 9 + 93 = 666.

It is an interprime number because it is at equal distance from previous prime (21909363953) and next prime (21909364033).

It is not a de Polignac number, because 21909363993 - 2⁸ = 21909363737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21909363953) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 624546 + ... + 658692.

It is an arithmetic number, because the mean of its divisors is an integer number (1438757684).

Almost surely, 2^21909363993 is an apocalyptic number.

It is an amenable number.

21909363993 is a deficient number, since it is larger than the sum of its proper divisors (12620820423).

21909363993 is a wasteful number, since it uses less digits than its factorization.

21909363993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40645 (or 40642 counting only the distinct ones).

The product of its (nonzero) digits is 2125764, while the sum is 54.

The spelling of 21909363993 in words is "twenty-one billion, nine hundred nine million, three hundred sixty-three thousand, nine hundred ninety-three".