23211661 has 4 divisors (see below), whose sum is σ = 25321824. Its totient is φ = 21101500.

The previous prime is 23211637. The next prime is 23211677. The reversal of 23211661 is 16611232.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23211661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23211611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1055065 + ... + 1055086.

It is an arithmetic number, because the mean of its divisors is an integer number (6330456).

Almost surely, 2^23211661 is an apocalyptic number.

It is an amenable number.

23211661 is a deficient number, since it is larger than the sum of its proper divisors (2110163).

23211661 is a wasteful number, since it uses less digits than its factorization.

23211661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2110162.

The product of its digits is 432, while the sum is 22.

The square root of 23211661 is about 4817.8481711237. The cubic root of 23211661 is about 285.2564061636.

Adding to 23211661 its reverse (16611232), we get a palindrome (39822893).

The spelling of 23211661 in words is "twenty-three million, two hundred eleven thousand, six hundred sixty-one".