19988321401 has 4 divisors (see below), whose sum is σ = 20015591332. Its totient is φ = 19961051472.

The previous prime is 19988321399. The next prime is 19988321443. The reversal of 19988321401 is 10412388991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10412388991 = 181 ⋅57527011.

It can be written as a sum of positive squares in 2 ways, for example, as 8556435001 + 11431886400 = 92501^2 + 106920^2 .

It is a cyclic number.

It is not a de Polignac number, because 19988321401 - 2¹ = 19988321399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19988321471) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13633866 + ... + 13635331.

It is an arithmetic number, because the mean of its divisors is an integer number (5003897833).

Almost surely, 2^19988321401 is an apocalyptic number.

It is an amenable number.

19988321401 is a deficient number, since it is larger than the sum of its proper divisors (27269931).

19988321401 is an equidigital number, since it uses as much as digits as its factorization.

19988321401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27269930.

The product of its (nonzero) digits is 124416, while the sum is 46.

The spelling of 19988321401 in words is "nineteen billion, nine hundred eighty-eight million, three hundred twenty-one thousand, four hundred one".