198551421 has 6 divisors (see below), whose sum is σ = 286796510. Its totient is φ = 132367608.

The previous prime is 198551417. The next prime is 198551471. The reversal of 198551421 is 124155891.

It can be written as a sum of positive squares in only one way, i.e., 161645796 + 36905625 = 12714^2 + 6075^2 .

It is not a de Polignac number, because 198551421 - 2² = 198551417 is a prime.

It is a super-2 number, since 2×198551421² = 78845333562238482, which contains 22 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 (198551471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11030626 + ... + 11030643.

Almost surely, 2^198551421 is an apocalyptic number.

It is an amenable number.

198551421 is a deficient number, since it is larger than the sum of its proper divisors (88245089).

198551421 is a wasteful number, since it uses less digits than its factorization.

198551421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22061275 (or 22061272 counting only the distinct ones).

The product of its digits is 14400, while the sum is 36.

The square root of 198551421 is about 14090.8275484444. The cubic root of 198551421 is about 583.3882349052.

The spelling of 198551421 in words is "one hundred ninety-eight million, five hundred fifty-one thousand, four hundred twenty-one".