40136965721 has 2 divisors, whose sum is σ = 40136965722. Its totient is φ = 40136965720.

The previous prime is 40136965679. The next prime is 40136965723. The reversal of 40136965721 is 12756963104.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29582280025 + 10554685696 = 171995^2 + 102736^2 .

It is a cyclic number.

It is not a de Polignac number, because 40136965721 - 2⁶ = 40136965657 is a prime.

It is a super-2 number, since 2×40136965721² (a number of 22 digits) contains 22 as substring.

Together with 40136965723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (40136965723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20068482860 + 20068482861.

It is an arithmetic number, because the mean of its divisors is an integer number (20068482861).

Almost surely, 2^40136965721 is an apocalyptic number.

It is an amenable number.

40136965721 is a deficient number, since it is larger than the sum of its proper divisors (1).

40136965721 is an equidigital number, since it uses as much as digits as its factorization.

40136965721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 272160, while the sum is 44.

The spelling of 40136965721 in words is "forty billion, one hundred thirty-six million, nine hundred sixty-five thousand, seven hundred twenty-one".