73978787831 has 4 divisors (see below), whose sum is σ = 79669463832. Its totient is φ = 68288111832.

The previous prime is 73978787821. The next prime is 73978787843. The reversal of 73978787831 is 13878787937.

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 73978787831 - 2³⁴ = 56798918647 is a prime.

It is a super-2 number, since 2×73978787831² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (73978787821) 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, 2845337981 + ... + 2845338006.

It is an arithmetic number, because the mean of its divisors is an integer number (19917365958).

Almost surely, 2^73978787831 is an apocalyptic number.

73978787831 is a deficient number, since it is larger than the sum of its proper divisors (5690676001).

73978787831 is a wasteful number, since it uses less digits than its factorization.

73978787831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5690676000.

The product of its digits is 99574272, while the sum is 68.

The spelling of 73978787831 in words is "seventy-three billion, nine hundred seventy-eight million, seven hundred eighty-seven thousand, eight hundred thirty-one".