198660155690 has 8 divisors (see below), whose sum is σ = 357588280260. Its totient is φ = 79464062272.

The previous prime is 198660155623. The next prime is 198660155699. The reversal of 198660155690 is 96551066891.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 190538361049 + 8121794641 = 436507^2 + 90121^2 .

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

It is a super-2 number, since 2×198660155690² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (198660155699) 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, 9933007775 + ... + 9933007794.

Almost surely, 2^198660155690 is an apocalyptic number.

198660155690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

198660155690 is a deficient number, since it is larger than the sum of its proper divisors (158928124570).

198660155690 is a wasteful number, since it uses less digits than its factorization.

198660155690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19866015576.

The product of its (nonzero) digits is 3499200, while the sum is 56.

The spelling of 198660155690 in words is "one hundred ninety-eight billion, six hundred sixty million, one hundred fifty-five thousand, six hundred ninety".