15228961661 has 4 divisors (see below), whose sum is σ = 15754098300. Its totient is φ = 14703825024.

The previous prime is 15228961651. The next prime is 15228961663. The reversal of 15228961661 is 16616982251.

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 11285875225 + 3943086436 = 106235^2 + 62794^2 .

It is a cyclic number.

It is not a de Polignac number, because 15228961661 - 2¹⁸ = 15228699517 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 (15228961663) 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, 262568276 + ... + 262568333.

It is an arithmetic number, because the mean of its divisors is an integer number (3938524575).

Almost surely, 2^15228961661 is an apocalyptic number.

It is an amenable number.

15228961661 is a deficient number, since it is larger than the sum of its proper divisors (525136639).

15228961661 is an equidigital number, since it uses as much as digits as its factorization.

15228961661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525136638.

The product of its digits is 311040, while the sum is 47.

The spelling of 15228961661 in words is "fifteen billion, two hundred twenty-eight million, nine hundred sixty-one thousand, six hundred sixty-one".