72716377021 has 4 divisors (see below), whose sum is σ = 72716950044. Its totient is φ = 72715804000.

The previous prime is 72716376991. The next prime is 72716377037. The reversal of 72716377021 is 12077361727.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12077361727 = 733 ⋅16476619.

It can be written as a sum of positive squares in 2 ways, for example, as 51989016121 + 20727360900 = 228011^2 + 143970^2 .

It is a cyclic number.

It is not a de Polignac number, because 72716377021 - 2²³ = 72707988413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72716377081) 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, 1960 + ... + 381361.

It is an arithmetic number, because the mean of its divisors is an integer number (18179237511).

Almost surely, 2^72716377021 is an apocalyptic number.

It is an amenable number.

72716377021 is a deficient number, since it is larger than the sum of its proper divisors (573023).

72716377021 is a wasteful number, since it uses less digits than its factorization.

72716377021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 573022.

The product of its (nonzero) digits is 172872, while the sum is 43.

The spelling of 72716377021 in words is "seventy-two billion, seven hundred sixteen million, three hundred seventy-seven thousand, twenty-one".