23641561 has 12 divisors (see below), whose sum is σ = 24836916. Its totient is φ = 22498560.

The previous prime is 23641559. The next prime is 23641573. The reversal of 23641561 is 16514632.

It can be written as a sum of positive squares in 2 ways, for example, as 9803161 + 13838400 = 3131^2 + 3720^2 .

It is not a de Polignac number, because 23641561 - 2¹ = 23641559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23641511) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69985 + ... + 70321.

It is an arithmetic number, because the mean of its divisors is an integer number (2069743).

Almost surely, 2^23641561 is an apocalyptic number.

It is an amenable number.

23641561 is a deficient number, since it is larger than the sum of its proper divisors (1195355).

23641561 is an equidigital number, since it uses as much as digits as its factorization.

23641561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 472 (or 441 counting only the distinct ones).

The product of its digits is 4320, while the sum is 28.

The square root of 23641561 is about 4862.2588372073. The cubic root of 23641561 is about 287.0067094871.

The spelling of 23641561 in words is "twenty-three million, six hundred forty-one thousand, five hundred sixty-one".