78120350491 has 4 divisors (see below), whose sum is σ = 79937102872. Its totient is φ = 76303598112.

The previous prime is 78120350489. The next prime is 78120350507. The reversal of 78120350491 is 19405302187.

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

It is a cyclic number.

It is not a de Polignac number, because 78120350491 - 2¹ = 78120350489 is a prime.

It is a super-2 number, since 2×78120350491² (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 (78120350401) 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, 908376126 + ... + 908376211.

It is an arithmetic number, because the mean of its divisors is an integer number (19984275718).

Almost surely, 2^78120350491 is an apocalyptic number.

78120350491 is a deficient number, since it is larger than the sum of its proper divisors (1816752381).

78120350491 is a wasteful number, since it uses less digits than its factorization.

78120350491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1816752380.

The product of its (nonzero) digits is 60480, while the sum is 40.

The spelling of 78120350491 in words is "seventy-eight billion, one hundred twenty million, three hundred fifty thousand, four hundred ninety-one".