1998984457 has 12 divisors (see below), whose sum is σ = 2151906588. Its totient is φ = 1850496000.

The previous prime is 1998984431. The next prime is 1998984467. The reversal of 1998984457 is 7544898991.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 82646281 + 1916338176 = 9091^2 + 43776^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1998984457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1998984467) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 47457 + ... + 79057.

It is an arithmetic number, because the mean of its divisors is an integer number (179325549).

Almost surely, 2^1998984457 is an apocalyptic number.

1998984457 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1998984457 is a deficient number, since it is larger than the sum of its proper divisors (152922131).

1998984457 is an equidigital number, since it uses as much as digits as its factorization.

1998984457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31740 (or 31679 counting only the distinct ones).

The product of its digits is 26127360, while the sum is 64.

The square root of 1998984457 is about 44710.0039923953. The cubic root of 1998984457 is about 1259.7077631234.

The spelling of 1998984457 in words is "one billion, nine hundred ninety-eight million, nine hundred eighty-four thousand, four hundred fifty-seven".