40129778257 has 2 divisors, whose sum is σ = 40129778258. Its totient is φ = 40129778256.

The previous prime is 40129778189. The next prime is 40129778261. The reversal of 40129778257 is 75287792104.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40054418496 + 75359761 = 200136^2 + 8681^2 .

It is a cyclic number.

It is not a de Polignac number, because 40129778257 - 2²⁷ = 39995560529 is a prime.

It is a super-2 number, since 2×40129778257² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (40129778657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20064889128 + 20064889129.

It is an arithmetic number, because the mean of its divisors is an integer number (20064889129).

Almost surely, 2^40129778257 is an apocalyptic number.

It is an amenable number.

40129778257 is a deficient number, since it is larger than the sum of its proper divisors (1).

40129778257 is an equidigital number, since it uses as much as digits as its factorization.

40129778257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1975680, while the sum is 52.

The spelling of 40129778257 in words is "forty billion, one hundred twenty-nine million, seven hundred seventy-eight thousand, two hundred fifty-seven".