198678690 has 128 divisors (see below), whose sum is σ = 625213440. Its totient is φ = 43934400.

The previous prime is 198678671. The next prime is 198678709. The reversal of 198678690 is 96876891.

It is an interprime number because it is at equal distance from previous prime (198678671) and next prime (198678709).

It is a super-2 number, since 2×198678690² = 78946443720232200, which contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 56895 + ... + 60285.

It is an arithmetic number, because the mean of its divisors is an integer number (4884480).

Almost surely, 2^198678690 is an apocalyptic number.

198678690 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 198678690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (312606720).

198678690 is an abundant number, since it is smaller than the sum of its proper divisors (426534750).

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

198678690 is a wasteful number, since it uses less digits than its factorization.

198678690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3445 (or 3439 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 54.

The square root of 198678690 is about 14095.3428479055. The cubic root of 198678690 is about 583.5128564914.

The spelling of 198678690 in words is "one hundred ninety-eight million, six hundred seventy-eight thousand, six hundred ninety".