1231998 has 32 divisors (see below), whose sum is σ = 2643840. Its totient is φ = 381600.

The previous prime is 1231987. The next prime is 1231999. The reversal of 1231998 is 8991321.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231999) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11461 + ... + 11567.

It is an arithmetic number, because the mean of its divisors is an integer number (82620).

2^1231998 is an apocalyptic number.

1231998 is an abundant number, since it is smaller than the sum of its proper divisors (1411842).

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

1231998 is a wasteful number, since it uses less digits than its factorization.

1231998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232.

The product of its digits is 3888, while the sum is 33.

The square root of 1231998 is about 1109.9540531031. The cubic root of 1231998 is about 107.2021102094.

The spelling of 1231998 in words is "one million, two hundred thirty-one thousand, nine hundred ninety-eight".