75572913721 has 4 divisors (see below), whose sum is σ = 80018379252. Its totient is φ = 71127448192.

The previous prime is 75572913683. The next prime is 75572913761. The reversal of 75572913721 is 12731927557.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 51529000000 + 24043913721 = 227000^2 + 155061^2 .

It is a cyclic number.

It is not a de Polignac number, because 75572913721 - 2⁹ = 75572913209 is a prime.

It is a super-2 number, since 2×75572913721² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (75572913761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2222732740 + ... + 2222732773.

It is an arithmetic number, because the mean of its divisors is an integer number (20004594813).

Almost surely, 2^75572913721 is an apocalyptic number.

It is an amenable number.

75572913721 is a deficient number, since it is larger than the sum of its proper divisors (4445465531).

75572913721 is a wasteful number, since it uses less digits than its factorization.

75572913721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4445465530.

The product of its digits is 926100, while the sum is 49.

The spelling of 75572913721 in words is "seventy-five billion, five hundred seventy-two million, nine hundred thirteen thousand, seven hundred twenty-one".