23121491 has 2 divisors, whose sum is σ = 23121492. Its totient is φ = 23121490.

The previous prime is 23121481. The next prime is 23121517. The reversal of 23121491 is 19412132.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 23121491 - 2¹⁴ = 23105107 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (23121421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11560745 + 11560746.

It is an arithmetic number, because the mean of its divisors is an integer number (11560746).

Almost surely, 2^23121491 is an apocalyptic number.

23121491 is a deficient number, since it is larger than the sum of its proper divisors (1).

23121491 is an equidigital number, since it uses as much as digits as its factorization.

23121491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 23.

The square root of 23121491 is about 4808.4811531293. The cubic root of 23121491 is about 284.8865496944.

The spelling of 23121491 in words is "twenty-three million, one hundred twenty-one thousand, four hundred ninety-one".