7572315661 has 4 divisors (see below), whose sum is σ = 8017746012. Its totient is φ = 7126885312.

The previous prime is 7572315637. The next prime is 7572315721. The reversal of 7572315661 is 1665132757.

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 5156101636 + 2416214025 = 71806^2 + 49155^2 .

It is a cyclic number.

It is not a de Polignac number, because 7572315661 - 2⁵ = 7572315629 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 (7572315601) 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, 222715150 + ... + 222715183.

It is an arithmetic number, because the mean of its divisors is an integer number (2004436503).

Almost surely, 2^7572315661 is an apocalyptic number.

It is an amenable number.

7572315661 is a deficient number, since it is larger than the sum of its proper divisors (445430351).

7572315661 is a wasteful number, since it uses less digits than its factorization.

7572315661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445430350.

The product of its digits is 264600, while the sum is 43.

The square root of 7572315661 is about 87019.0534365894. The cubic root of 7572315661 is about 1963.7049577500.

The spelling of 7572315661 in words is "seven billion, five hundred seventy-two million, three hundred fifteen thousand, six hundred sixty-one".