21791314187 has 16 divisors (see below), whose sum is σ = 24301347840. Its totient is φ = 19418974848.

The previous prime is 21791314157. The next prime is 21791314213. The reversal of 21791314187 is 78141319712.

It is a cyclic number.

It is not a de Polignac number, because 21791314187 - 2⁸ = 21791313931 is a prime.

It is a super-3 number, since 3×21791314187³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21791314157) 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, 578318 + ... + 614844.

It is an arithmetic number, because the mean of its divisors is an integer number (1518834240).

Almost surely, 2^21791314187 is an apocalyptic number.

21791314187 is a deficient number, since it is larger than the sum of its proper divisors (2510033653).

21791314187 is a wasteful number, since it uses less digits than its factorization.

21791314187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38410.

The product of its digits is 84672, while the sum is 44.

The spelling of 21791314187 in words is "twenty-one billion, seven hundred ninety-one million, three hundred fourteen thousand, one hundred eighty-seven".