991203898 has 8 divisors (see below), whose sum is σ = 1490629140. Its totient is φ = 494327520.

The previous prime is 991203893. The next prime is 991203901. The reversal of 991203898 is 898302199.

It can be written as a sum of positive squares in 2 ways, for example, as 989291209 + 1912689 = 31453^2 + 1383^2 .

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

It is not an unprimeable number, because it can be changed into a prime (991203893) 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, 636243 + ... + 637798.

Almost surely, 2^991203898 is an apocalyptic number.

991203898 is a deficient number, since it is larger than the sum of its proper divisors (499425242).

991203898 is a wasteful number, since it uses less digits than its factorization.

991203898 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1274432.

The product of its (nonzero) digits is 279936, while the sum is 49.

The square root of 991203898 is about 31483.3908275459. The cubic root of 991203898 is about 997.0593269184.

The spelling of 991203898 in words is "nine hundred ninety-one million, two hundred three thousand, eight hundred ninety-eight".