78201379961 has 4 divisors (see below), whose sum is σ = 80897979300. Its totient is φ = 75504780624.

The previous prime is 78201379943. The next prime is 78201379973. The reversal of 78201379961 is 16997310287.

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 55053583225 + 23147796736 = 234635^2 + 152144^2 .

It is a cyclic number.

It is not a de Polignac number, because 78201379961 - 2⁶ = 78201379897 is a prime.

It is a super-2 number, since 2×78201379961² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78201379981) 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, 1348299626 + ... + 1348299683.

It is an arithmetic number, because the mean of its divisors is an integer number (20224494825).

Almost surely, 2^78201379961 is an apocalyptic number.

It is an amenable number.

78201379961 is a deficient number, since it is larger than the sum of its proper divisors (2696599339).

78201379961 is a wasteful number, since it uses less digits than its factorization.

78201379961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2696599338.

The product of its (nonzero) digits is 1143072, while the sum is 53.

The spelling of 78201379961 in words is "seventy-eight billion, two hundred one million, three hundred seventy-nine thousand, nine hundred sixty-one".