21737115791 has 2 divisors, whose sum is σ = 21737115792. Its totient is φ = 21737115790.

The previous prime is 21737115781. The next prime is 21737115853. The reversal of 21737115791 is 19751173712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21737115791 - 2¹⁴ = 21737099407 is a prime.

It is a super-2 number, since 2×21737115791² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21737115781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10868557895 + 10868557896.

It is an arithmetic number, because the mean of its divisors is an integer number (10868557896).

Almost surely, 2^21737115791 is an apocalyptic number.

21737115791 is a deficient number, since it is larger than the sum of its proper divisors (1).

21737115791 is an equidigital number, since it uses as much as digits as its factorization.

21737115791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 92610, while the sum is 44.

The spelling of 21737115791 in words is "twenty-one billion, seven hundred thirty-seven million, one hundred fifteen thousand, seven hundred ninety-one".