38172745661 has 4 divisors (see below), whose sum is σ = 38181208572. Its totient is φ = 38164282752.

The previous prime is 38172745609. The next prime is 38172745687. The reversal of 38172745661 is 16654727183.

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 5262436 + 38167483225 = 2294^2 + 195365^2 .

It is a cyclic number.

It is not a de Polignac number, because 38172745661 - 2¹⁴ = 38172729277 is a prime.

It is a super-2 number, since 2×38172745661² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38172745361) 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, 4224686 + ... + 4233711.

It is an arithmetic number, because the mean of its divisors is an integer number (9545302143).

Almost surely, 2^38172745661 is an apocalyptic number.

It is an amenable number.

38172745661 is a deficient number, since it is larger than the sum of its proper divisors (8462911).

38172745661 is an equidigital number, since it uses as much as digits as its factorization.

38172745661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8462910.

The product of its digits is 1693440, while the sum is 50.

The spelling of 38172745661 in words is "thirty-eight billion, one hundred seventy-two million, seven hundred forty-five thousand, six hundred sixty-one".