123642261 has 8 divisors (see below), whose sum is σ = 183173760. Its totient is φ = 82428156.

The previous prime is 123642251. The next prime is 123642287. The reversal of 123642261 is 162246321.

123642261 is a `hidden beast` number, since 1 + 236 + 422 + 6 + 1 = 666.

It is not a de Polignac number, because 123642261 - 2¹⁴ = 123625877 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 4579343 = 123642261 / (1 + 2 + 3 + 6 + 4 + 2 + 2 + 6 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123642251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2289645 + ... + 2289698.

It is an arithmetic number, because the mean of its divisors is an integer number (22896720).

Almost surely, 2^123642261 is an apocalyptic number.

It is an amenable number.

123642261 is a deficient number, since it is larger than the sum of its proper divisors (59531499).

123642261 is an equidigital number, since it uses as much as digits as its factorization.

123642261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4579352 (or 4579346 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 123642261 is about 11119.4541682584. The cubic root of 123642261 is about 498.1830869848.

Adding to 123642261 its reverse (162246321), we get a palindrome (285888582).

The spelling of 123642261 in words is "one hundred twenty-three million, six hundred forty-two thousand, two hundred sixty-one".