198851612257 has 4 divisors (see below), whose sum is σ = 203476068400. Its totient is φ = 194227156116.

The previous prime is 198851612221. The next prime is 198851612261. The reversal of 198851612257 is 752216158891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 752216158891 = 133583 ⋅5631077.

It is a cyclic number.

It is not a de Polignac number, because 198851612257 - 2¹⁵ = 198851579489 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 198851612198 and 198851612207.

It is not an unprimeable number, because it can be changed into a prime (198851612287) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2312228007 + ... + 2312228092.

It is an arithmetic number, because the mean of its divisors is an integer number (50869017100).

Almost surely, 2^198851612257 is an apocalyptic number.

It is an amenable number.

198851612257 is a deficient number, since it is larger than the sum of its proper divisors (4624456143).

198851612257 is an equidigital number, since it uses as much as digits as its factorization.

198851612257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4624456142.

The product of its digits is 2419200, while the sum is 55.

The spelling of 198851612257 in words is "one hundred ninety-eight billion, eight hundred fifty-one million, six hundred twelve thousand, two hundred fifty-seven".