40691780729 has 2 divisors, whose sum is σ = 40691780730. Its totient is φ = 40691780728.

The previous prime is 40691780687. The next prime is 40691780747. The reversal of 40691780729 is 92708719604.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38085474025 + 2606306704 = 195155^2 + 51052^2 .

It is a cyclic number.

It is not a de Polignac number, because 40691780729 - 2⁸ = 40691780473 is a prime.

It is not a weakly prime, because it can be changed into another prime (40691780029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20345890364 + 20345890365.

It is an arithmetic number, because the mean of its divisors is an integer number (20345890365).

Almost surely, 2^40691780729 is an apocalyptic number.

It is an amenable number.

40691780729 is a deficient number, since it is larger than the sum of its proper divisors (1).

40691780729 is an equidigital number, since it uses as much as digits as its factorization.

40691780729 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1524096, while the sum is 53.

The spelling of 40691780729 in words is "forty billion, six hundred ninety-one million, seven hundred eighty thousand, seven hundred twenty-nine".