72705944657 has 4 divisors (see below), whose sum is σ = 72825724416. Its totient is φ = 72586164900.

The previous prime is 72705944653. The next prime is 72705944659. The reversal of 72705944657 is 75644950727.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75644950727 = 557 ⋅135807811.

It is a cyclic number.

It is not a de Polignac number, because 72705944657 - 2² = 72705944653 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72705944653) 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, 59888969 + ... + 59890182.

It is an arithmetic number, because the mean of its divisors is an integer number (18206431104).

Almost surely, 2^72705944657 is an apocalyptic number.

It is an amenable number.

72705944657 is a deficient number, since it is larger than the sum of its proper divisors (119779759).

72705944657 is a wasteful number, since it uses less digits than its factorization.

72705944657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119779758.

The product of its (nonzero) digits is 14817600, while the sum is 56.

The spelling of 72705944657 in words is "seventy-two billion, seven hundred five million, nine hundred forty-four thousand, six hundred fifty-seven".