198971621 has 8 divisors (see below), whose sum is σ = 215576064. Its totient is φ = 182911680.

The previous prime is 198971611. The next prime is 198971623. The reversal of 198971621 is 126179891.

198971621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 198971621 - 2⁶ = 198971557 is a prime.

It is a super-3 number, since 3×198971621³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198971623) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135365 + ... + 136826.

It is an arithmetic number, because the mean of its divisors is an integer number (26947008).

Almost surely, 2^198971621 is an apocalyptic number.

It is an amenable number.

198971621 is a deficient number, since it is larger than the sum of its proper divisors (16604443).

198971621 is a wasteful number, since it uses less digits than its factorization.

198971621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272251.

The product of its digits is 54432, while the sum is 44.

The square root of 198971621 is about 14105.7300768163. The cubic root of 198971621 is about 583.7994919422.

The spelling of 198971621 in words is "one hundred ninety-eight million, nine hundred seventy-one thousand, six hundred twenty-one".