23198021 has 24 divisors (see below), whose sum is σ = 29723904. Its totient is φ = 17902080.

The previous prime is 23198009. The next prime is 23198023. The reversal of 23198021 is 12089132.

It is not a de Polignac number, because 23198021 - 2⁶ = 23197957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23198023) 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 23 ways as a sum of consecutive naturals, for example, 103916 + ... + 104138.

It is an arithmetic number, because the mean of its divisors is an integer number (1238496).

Almost surely, 2^23198021 is an apocalyptic number.

It is an amenable number.

23198021 is a deficient number, since it is larger than the sum of its proper divisors (6525883).

23198021 is a wasteful number, since it uses less digits than its factorization.

23198021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441 (or 434 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 23198021 is about 4816.4323933800. The cubic root of 23198021 is about 285.2005196019.

Subtracting from 23198021 its reverse (12089132), we obtain a square (11108889 = 3333²).

The spelling of 23198021 in words is "twenty-three million, one hundred ninety-eight thousand, twenty-one".