19980387904 has 21 divisors (see below), whose sum is σ = 39650826337. Its totient is φ = 9989628544.

The previous prime is 19980387877. The next prime is 19980387943. The reversal of 19980387904 is 40978308991.

It is a happy number.

The square root of 19980387904 is 141352.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 3962954304 + 16017433600 = 62952^2 + 126560^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1121982 + ... + 1139650.

Almost surely, 2^19980387904 is an apocalyptic number.

19980387904 is the 141352-nd square number.

It is an amenable number.

19980387904 is a deficient number, since it is larger than the sum of its proper divisors (19670438433).

19980387904 is an frugal number, since it uses more digits than its factorization.

19980387904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35350 (or 17671 counting only the distinct ones).

The product of its (nonzero) digits is 3919104, while the sum is 58.

The spelling of 19980387904 in words is "nineteen billion, nine hundred eighty million, three hundred eighty-seven thousand, nine hundred four".