78379775081 has 4 divisors (see below), whose sum is σ = 80202560592. Its totient is φ = 76556989572.

The previous prime is 78379775039. The next prime is 78379775171. The reversal of 78379775081 is 18057797387.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78379775081 is a prime.

It is a super-2 number, since 2×78379775081² (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 (78379775281) 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, 911392691 + ... + 911392776.

It is an arithmetic number, because the mean of its divisors is an integer number (20050640148).

Almost surely, 2^78379775081 is an apocalyptic number.

It is an amenable number.

78379775081 is a deficient number, since it is larger than the sum of its proper divisors (1822785511).

78379775081 is a wasteful number, since it uses less digits than its factorization.

78379775081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1822785510.

The product of its (nonzero) digits is 20744640, while the sum is 62.

The spelling of 78379775081 in words is "seventy-eight billion, three hundred seventy-nine million, seven hundred seventy-five thousand, eighty-one".