1987998039 has 32 divisors (see below), whose sum is σ = 3067238400. Its totient is φ = 1271168640.

The previous prime is 1987998013. The next prime is 1987998109. The reversal of 1987998039 is 9308997891.

It is not a de Polignac number, because 1987998039 - 2¹¹ = 1987995991 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1987998239) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 84072 + ... + 105090.

It is an arithmetic number, because the mean of its divisors is an integer number (95851200).

Almost surely, 2^1987998039 is an apocalyptic number.

1987998039 is a deficient number, since it is larger than the sum of its proper divisors (1079240361).

1987998039 is a wasteful number, since it uses less digits than its factorization.

1987998039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21172 (or 21166 counting only the distinct ones).

The product of its (nonzero) digits is 8817984, while the sum is 63.

The square root of 1987998039 is about 44586.9716284926. The cubic root of 1987998039 is about 1257.3957378047.

The spelling of 1987998039 in words is "one billion, nine hundred eighty-seven million, nine hundred ninety-eight thousand, thirty-nine".