78166273577 has 12 divisors (see below), whose sum is σ = 91318376916. Its totient is φ = 66712101120.

The previous prime is 78166273573. The next prime is 78166273589. The reversal of 78166273577 is 77537266187.

It can be written as a sum of positive squares in 2 ways, for example, as 55213720576 + 22952553001 = 234976^2 + 151501^2 .

It is not a de Polignac number, because 78166273577 - 2² = 78166273573 is a prime.

It is a super-2 number, since 2×78166273577² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (59) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78166273573) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3411824 + ... + 3434657.

It is an arithmetic number, because the mean of its divisors is an integer number (7609864743).

Almost surely, 2^78166273577 is an apocalyptic number.

It is an amenable number.

78166273577 is a deficient number, since it is larger than the sum of its proper divisors (13152103339).

78166273577 is a wasteful number, since it uses less digits than its factorization.

78166273577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6846728 (or 6846721 counting only the distinct ones).

The product of its digits is 20744640, while the sum is 59.

The spelling of 78166273577 in words is "seventy-eight billion, one hundred sixty-six million, two hundred seventy-three thousand, five hundred seventy-seven".