1982991123 has 12 divisors (see below), whose sum is σ = 2892130800. Its totient is φ = 1309158576.

The previous prime is 1982991103. The next prime is 1982991137. The reversal of 1982991123 is 3211992891.

It is not a de Polignac number, because 1982991123 - 2⁵ = 1982991091 is a prime.

It is a super-2 number, since 2×1982991123² = 7864507587793602258, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1982991103) 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, 1068648 + ... + 1070501.

It is an arithmetic number, because the mean of its divisors is an integer number (241010900).

Almost surely, 2^1982991123 is an apocalyptic number.

1982991123 is a deficient number, since it is larger than the sum of its proper divisors (909139677).

1982991123 is a wasteful number, since it uses less digits than its factorization.

1982991123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2139258 (or 2139255 counting only the distinct ones).

The product of its digits is 69984, while the sum is 45.

The square root of 1982991123 is about 44530.7884839242. The cubic root of 1982991123 is about 1256.3392364916.

The spelling of 1982991123 in words is "one billion, nine hundred eighty-two million, nine hundred ninety-one thousand, one hundred twenty-three".