198155256390 has 960 divisors, whose sum is σ = 709551000576. Its totient is φ = 38909984256.

The previous prime is 198155256347. The next prime is 198155256461. The reversal of 198155256390 is 93652551891.

198155256390 is a `hidden beast` number, since 1 + 9 + 8 + 1 + 552 + 56 + 39 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

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 479 ways as a sum of consecutive naturals, for example, 5355547452 + ... + 5355547488.

Almost surely, 2^198155256390 is an apocalyptic number.

198155256390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 198155256390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (354775500288).

198155256390 is an abundant number, since it is smaller than the sum of its proper divisors (511395744186).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

198155256390 is an equidigital number, since it uses as much as digits as its factorization.

198155256390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127 (or 90 counting only the distinct ones).

The product of its (nonzero) digits is 2916000, while the sum is 54.

The spelling of 198155256390 in words is "one hundred ninety-eight billion, one hundred fifty-five million, two hundred fifty-six thousand, three hundred ninety".