23509861 has 6 divisors (see below), whose sum is σ = 24974450. Its totient is φ = 22126656.

The previous prime is 23509813. The next prime is 23509867. The reversal of 23509861 is 16890532.

It can be written as a sum of positive squares in 3 ways, for example, as 2579236 + 20930625 = 1606^2 + 4575^2 .

It is a de Polignac number, because none of the positive numbers 2^k-23509861 is a prime.

It is a super-3 number, since 3×23509861³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23509867) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 40386 + ... + 40963.

Almost surely, 2^23509861 is an apocalyptic number.

It is an amenable number.

23509861 is a deficient number, since it is larger than the sum of its proper divisors (1464589).

23509861 is an equidigital number, since it uses as much as digits as its factorization.

23509861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81383 (or 81366 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 23509861 is about 4848.6968352332. The cubic root of 23509861 is about 286.4727742109.

The spelling of 23509861 in words is "twenty-three million, five hundred nine thousand, eight hundred sixty-one".