23671981 has 2 divisors, whose sum is σ = 23671982. Its totient is φ = 23671980.

The previous prime is 23671969. The next prime is 23671987. The reversal of 23671981 is 18917632.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13213225 + 10458756 = 3635^2 + 3234^2 .

It is a cyclic number.

It is not a de Polignac number, because 23671981 - 2⁹ = 23671469 is a prime.

It is a super-2 number, since 2×23671981² = 1120725368928722, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 23671981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23671987) 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 as a sum of consecutive naturals, namely, 11835990 + 11835991.

It is an arithmetic number, because the mean of its divisors is an integer number (11835991).

Almost surely, 2^23671981 is an apocalyptic number.

It is an amenable number.

23671981 is a deficient number, since it is larger than the sum of its proper divisors (1).

23671981 is an equidigital number, since it uses as much as digits as its factorization.

23671981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 37.

The square root of 23671981 is about 4865.3860072969. The cubic root of 23671981 is about 287.1297555374.

The spelling of 23671981 in words is "twenty-three million, six hundred seventy-one thousand, nine hundred eighty-one".