19401420408 has 128 divisors (see below), whose sum is σ = 52625401920. Its totient is φ = 5937684480.

The previous prime is 19401420407. The next prime is 19401420419. The reversal of 19401420408 is 80402410491.

It is a super-2 number, since 2×19401420408² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19401420403) 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, 3911466 + ... + 3916422.

Almost surely, 2^19401420408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19401420408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26312700960).

19401420408 is an abundant number, since it is smaller than the sum of its proper divisors (33223981512).

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

19401420408 is a wasteful number, since it uses less digits than its factorization.

19401420408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5217 (or 5213 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

Adding to 19401420408 its reverse (80402410491), we get a palindrome (99803830899).

The spelling of 19401420408 in words is "nineteen billion, four hundred one million, four hundred twenty thousand, four hundred eight".