1998455878 has 8 divisors (see below), whose sum is σ = 3128017968. Its totient is φ = 955783224.

The previous prime is 1998455863. The next prime is 1998455881. The reversal of 1998455878 is 8785548991.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21722301 + ... + 21722392.

It is an arithmetic number, because the mean of its divisors is an integer number (391002246).

Almost surely, 2^1998455878 is an apocalyptic number.

1998455878 is a deficient number, since it is larger than the sum of its proper divisors (1129562090).

1998455878 is a wasteful number, since it uses less digits than its factorization.

1998455878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43444718.

The product of its digits is 29030400, while the sum is 64.

The square root of 1998455878 is about 44704.0924077427. The cubic root of 1998455878 is about 1259.5967211114.

The spelling of 1998455878 in words is "one billion, nine hundred ninety-eight million, four hundred fifty-five thousand, eight hundred seventy-eight".