1983997638 has 160 divisors (see below), whose sum is σ = 5216327424. Its totient is φ = 551976768.

The previous prime is 1983997621. The next prime is 1983997649. The reversal of 1983997638 is 8367993891.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 10070956 + ... + 10071152.

Almost surely, 2^1983997638 is an apocalyptic number.

1983997638 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1983997638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2608163712).

1983997638 is an abundant number, since it is smaller than the sum of its proper divisors (3232329786).

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

1983997638 is a wasteful number, since it uses less digits than its factorization.

1983997638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408 (or 399 counting only the distinct ones).

The product of its digits is 17635968, while the sum is 63.

The square root of 1983997638 is about 44542.0883883996. The cubic root of 1983997638 is about 1256.5517623044.

The spelling of 1983997638 in words is "one billion, nine hundred eighty-three million, nine hundred ninety-seven thousand, six hundred thirty-eight".