19801982 has 8 divisors (see below), whose sum is σ = 30079200. Its totient is φ = 9775584.

The previous prime is 19801961. The next prime is 19801997. The reversal of 19801982 is 28910891.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×19801982² = 784236982256648, which contains 22 as substring.

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, 62507 + ... + 62822.

It is an arithmetic number, because the mean of its divisors is an integer number (3759900).

Almost surely, 2^19801982 is an apocalyptic number.

19801982 is a deficient number, since it is larger than the sum of its proper divisors (10277218).

19801982 is a wasteful number, since it uses less digits than its factorization.

19801982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125410.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 19801982 is about 4449.9417973722. The cubic root of 19801982 is about 270.5429495047.

The spelling of 19801982 in words is "nineteen million, eight hundred one thousand, nine hundred eighty-two".