72777156431 has 4 divisors (see below), whose sum is σ = 83173893072. Its totient is φ = 62380419792.

The previous prime is 72777156421. The next prime is 72777156437. The reversal of 72777156431 is 13465177727.

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 72777156431 - 2¹⁸ = 72776894287 is a prime.

It is a super-2 number, since 2×72777156431² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72777156431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72777156437) 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, 5198368310 + ... + 5198368323.

It is an arithmetic number, because the mean of its divisors is an integer number (20793473268).

Almost surely, 2^72777156431 is an apocalyptic number.

72777156431 is a deficient number, since it is larger than the sum of its proper divisors (10396736641).

72777156431 is a wasteful number, since it uses less digits than its factorization.

72777156431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10396736640.

The product of its digits is 1728720, while the sum is 50.

The spelling of 72777156431 in words is "seventy-two billion, seven hundred seventy-seven million, one hundred fifty-six thousand, four hundred thirty-one".