78291984431 has 2 divisors, whose sum is σ = 78291984432. Its totient is φ = 78291984430.

The previous prime is 78291984403. The next prime is 78291984451. The reversal of 78291984431 is 13448919287.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78291984431 - 2²² = 78287790127 is a prime.

It is a super-2 number, since 2×78291984431² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78291984451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39145992215 + 39145992216.

It is an arithmetic number, because the mean of its divisors is an integer number (39145992216).

Almost surely, 2^78291984431 is an apocalyptic number.

78291984431 is a deficient number, since it is larger than the sum of its proper divisors (1).

78291984431 is an equidigital number, since it uses as much as digits as its factorization.

78291984431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3483648, while the sum is 56.

The spelling of 78291984431 in words is "seventy-eight billion, two hundred ninety-one million, nine hundred eighty-four thousand, four hundred thirty-one".