77875513081 has 4 divisors (see below), whose sum is σ = 78270820452. Its totient is φ = 77480205712.

The previous prime is 77875513057. The next prime is 77875513087. The reversal of 77875513081 is 18031557877.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 76399724025 + 1475789056 = 276405^2 + 38416^2 .

It is a cyclic number.

It is not a de Polignac number, because 77875513081 - 2⁹ = 77875512569 is a prime.

It is a super-2 number, since 2×77875513081² (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 (77875513087) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 197653390 + ... + 197653783.

It is an arithmetic number, because the mean of its divisors is an integer number (19567705113).

Almost surely, 2^77875513081 is an apocalyptic number.

It is an amenable number.

77875513081 is a deficient number, since it is larger than the sum of its proper divisors (395307371).

77875513081 is a wasteful number, since it uses less digits than its factorization.

77875513081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395307370.

The product of its (nonzero) digits is 1646400, while the sum is 52.

The spelling of 77875513081 in words is "seventy-seven billion, eight hundred seventy-five million, five hundred thirteen thousand, eighty-one".