198921457 has 12 divisors (see below), whose sum is σ = 237657280. Its totient is φ = 163087848.

The previous prime is 198921449. The next prime is 198921461. The reversal of 198921457 is 754129891.

It is not a de Polignac number, because 198921457 - 2³ = 198921449 is a prime.

It is a super-5 number, since 5×198921457⁵ (a number of 43 digits) contains 55555 as substring.

It is not an unprimeable number, because it can be changed into a prime (198921467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23157 + ... + 30562.

Almost surely, 2^198921457 is an apocalyptic number.

It is an amenable number.

198921457 is a deficient number, since it is larger than the sum of its proper divisors (38735823).

198921457 is an equidigital number, since it uses as much as digits as its factorization.

198921457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53772 (or 53749 counting only the distinct ones).

The product of its digits is 181440, while the sum is 46.

The square root of 198921457 is about 14103.9518220958. The cubic root of 198921457 is about 583.7504260184.

The spelling of 198921457 in words is "one hundred ninety-eight million, nine hundred twenty-one thousand, four hundred fifty-seven".