19901638880 has 192 divisors, whose sum is σ = 50703408000. Its totient is φ = 7355301888.

The previous prime is 19901638879. The next prime is 19901638903. The reversal of 19901638880 is 8883610991.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 55436141 + ... + 55436499.

It is an arithmetic number, because the mean of its divisors is an integer number (264080250).

Almost surely, 2^19901638880 is an apocalyptic number.

19901638880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19901638880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25351704000).

19901638880 is an abundant number, since it is smaller than the sum of its proper divisors (30801769120).

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

19901638880 is a wasteful number, since it uses less digits than its factorization.

19901638880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 709 (or 701 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 53.

The spelling of 19901638880 in words is "nineteen billion, nine hundred one million, six hundred thirty-eight thousand, eight hundred eighty".