27236131721 has 2 divisors, whose sum is σ = 27236131722. Its totient is φ = 27236131720.

The previous prime is 27236131691. The next prime is 27236131757. The reversal of 27236131721 is 12713163272.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26797690000 + 438441721 = 163700^2 + 20939^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27236131721 is a prime.

It is a super-2 number, since 2×27236131721² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (27236131781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13618065860 + 13618065861.

It is an arithmetic number, because the mean of its divisors is an integer number (13618065861).

Almost surely, 2^27236131721 is an apocalyptic number.

It is an amenable number.

27236131721 is a deficient number, since it is larger than the sum of its proper divisors (1).

27236131721 is an equidigital number, since it uses as much as digits as its factorization.

27236131721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21168, while the sum is 35.

Adding to 27236131721 its reverse (12713163272), we get a palindrome (39949294993).

The spelling of 27236131721 in words is "twenty-seven billion, two hundred thirty-six million, one hundred thirty-one thousand, seven hundred twenty-one".