1989491008 has 28 divisors (see below), whose sum is σ = 3953375380. Its totient is φ = 993364992.

The previous prime is 1989490981. The next prime is 1989491017. The reversal of 1989491008 is 8001949891.

It can be written as a sum of positive squares in 2 ways, for example, as 1729894464 + 259596544 = 41592^2 + 16112^2 .

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, 25708 + ... + 68116.

Almost surely, 2^1989491008 is an apocalyptic number.

It is an amenable number.

1989491008 is a deficient number, since it is larger than the sum of its proper divisors (1963884372).

1989491008 is an equidigital number, since it uses as much as digits as its factorization.

1989491008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43154 (or 43144 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 49.

The square root of 1989491008 is about 44603.7106976538. The cubic root of 1989491008 is about 1257.7104234135.

The spelling of 1989491008 in words is "one billion, nine hundred eighty-nine million, four hundred ninety-one thousand, eight".