72542078721 has 12 divisors (see below), whose sum is σ = 119752003072. Its totient is φ = 41452616376.

The previous prime is 72542078711. The next prime is 72542078723. The reversal of 72542078721 is 12787024527.

72542078721 is a `hidden beast` number, since 7 + 2 + 542 + 0 + 7 + 87 + 21 = 666.

It is not a de Polignac number, because 72542078721 - 2⁵ = 72542078689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72542078723) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 575730721 + ... + 575730846.

Almost surely, 2^72542078721 is an apocalyptic number.

It is an amenable number.

72542078721 is a deficient number, since it is larger than the sum of its proper divisors (47209924351).

72542078721 is a wasteful number, since it uses less digits than its factorization.

72542078721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1151461580 (or 1151461577 counting only the distinct ones).

The product of its (nonzero) digits is 439040, while the sum is 45.

The spelling of 72542078721 in words is "seventy-two billion, five hundred forty-two million, seventy-eight thousand, seven hundred twenty-one".