72777751 has 4 divisors (see below), whose sum is σ = 72855072. Its totient is φ = 72700432.

The previous prime is 72777737. The next prime is 72777781. The reversal of 72777751 is 15777727.

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 72777751 - 2²⁵ = 39223319 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72777698 and 72777707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72777721) 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, 37231 + ... + 39136.

It is an arithmetic number, because the mean of its divisors is an integer number (18213768).

Almost surely, 2^72777751 is an apocalyptic number.

72777751 is a deficient number, since it is larger than the sum of its proper divisors (77321).

72777751 is an equidigital number, since it uses as much as digits as its factorization.

72777751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77320.

The product of its digits is 168070, while the sum is 43.

The square root of 72777751 is about 8530.9876919381. The cubic root of 72777751 is about 417.5093542551.

The spelling of 72777751 in words is "seventy-two million, seven hundred seventy-seven thousand, seven hundred fifty-one".