19891812101 has 48 divisors (see below), whose sum is σ = 24723864000. Its totient is φ = 15911562240.

The previous prime is 19891812089. The next prime is 19891812103. The reversal of 19891812101 is 10121819891.

It is not a de Polignac number, because 19891812101 - 2¹⁰ = 19891811077 is a prime.

It is a super-2 number, since 2×19891812101² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19891812103) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 21411605 + ... + 21412533.

It is an arithmetic number, because the mean of its divisors is an integer number (515080500).

Almost surely, 2^19891812101 is an apocalyptic number.

It is an amenable number.

19891812101 is a deficient number, since it is larger than the sum of its proper divisors (4832051899).

19891812101 is a wasteful number, since it uses less digits than its factorization.

19891812101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1282 (or 1275 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 41.

The spelling of 19891812101 in words is "nineteen billion, eight hundred ninety-one million, eight hundred twelve thousand, one hundred one".