23661491 has 4 divisors (see below), whose sum is σ = 27041712. Its totient is φ = 20281272.

The previous prime is 23661487. The next prime is 23661499. The reversal of 23661491 is 19416632.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 23661491 - 2² = 23661487 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23661499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1690100 + ... + 1690113.

It is an arithmetic number, because the mean of its divisors is an integer number (6760428).

Almost surely, 2^23661491 is an apocalyptic number.

23661491 is a deficient number, since it is larger than the sum of its proper divisors (3380221).

23661491 is an equidigital number, since it uses as much as digits as its factorization.

23661491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3380220.

The product of its digits is 7776, while the sum is 32.

The square root of 23661491 is about 4864.3078644346. The cubic root of 23661491 is about 287.0873363844.

The spelling of 23661491 in words is "twenty-three million, six hundred sixty-one thousand, four hundred ninety-one".