77745272681 has 6 divisors (see below), whose sum is σ = 81272468970. Its totient is φ = 74365042928.

The previous prime is 77745272663. The next prime is 77745272699. The reversal of 77745272681 is 18627254777.

It is an interprime number because it is at equal distance from previous prime (77745272663) and next prime (77745272699).

It can be written as a sum of positive squares in only one way, i.e., 56481800281 + 21263472400 = 237659^2 + 145820^2 .

It is not a de Polignac number, because 77745272681 - 2⁶ = 77745272617 is a prime.

It is a super-2 number, since 2×77745272681² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77745272611) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 73482716 + ... + 73483773.

It is an arithmetic number, because the mean of its divisors is an integer number (13545411495).

Almost surely, 2^77745272681 is an apocalyptic number.

It is an amenable number.

77745272681 is a deficient number, since it is larger than the sum of its proper divisors (3527196289).

77745272681 is a wasteful number, since it uses less digits than its factorization.

77745272681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146966535 (or 146966512 counting only the distinct ones).

The product of its digits is 9219840, while the sum is 56.

The spelling of 77745272681 in words is "seventy-seven billion, seven hundred forty-five million, two hundred seventy-two thousand, six hundred eighty-one".