78291984436 has 24 divisors (see below), whose sum is σ = 140982153984. Its totient is φ = 38019933120.

The previous prime is 78291984431. The next prime is 78291984451. The reversal of 78291984436 is 63448919287.

It is a super-2 number, since 2×78291984436² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78291984431) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1033810 + ... + 1106953.

It is an arithmetic number, because the mean of its divisors is an integer number (5874256416).

Almost surely, 2^78291984436 is an apocalyptic number.

It is an amenable number.

78291984436 is a deficient number, since it is larger than the sum of its proper divisors (62690169548).

78291984436 is a wasteful number, since it uses less digits than its factorization.

78291984436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2141031 (or 2141029 counting only the distinct ones).

The product of its digits is 20901888, while the sum is 61.

The spelling of 78291984436 in words is "seventy-eight billion, two hundred ninety-one million, nine hundred eighty-four thousand, four hundred thirty-six".