23138581 has 16 divisors (see below), whose sum is σ = 25431408. Its totient is φ = 20966400.

The previous prime is 23138567. The next prime is 23138597. The reversal of 23138581 is 18583132.

It can be written as a sum of positive squares in 8 ways, for example, as 3478225 + 19660356 = 1865^2 + 4434^2 .

It is a cyclic number.

It is not a de Polignac number, because 23138581 - 2¹³ = 23130389 is a prime.

It is a super-2 number, since 2×23138581² = 1070787861387122, which contains 22 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 (23138501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54751 + ... + 55171.

It is an arithmetic number, because the mean of its divisors is an integer number (1589463).

Almost surely, 2^23138581 is an apocalyptic number.

It is an amenable number.

23138581 is a deficient number, since it is larger than the sum of its proper divisors (2292827).

23138581 is a wasteful number, since it uses less digits than its factorization.

23138581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 552.

The product of its digits is 5760, while the sum is 31.

The square root of 23138581 is about 4810.2578932943. The cubic root of 23138581 is about 284.9567226787.

The spelling of 23138581 in words is "twenty-three million, one hundred thirty-eight thousand, five hundred eighty-one".