19901916 has 48 divisors (see below), whose sum is σ = 52039680. Its totient is φ = 6577200.

The previous prime is 19901909. The next prime is 19901927. The reversal of 19901916 is 61910991.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12991 + ... + 14441.

It is an arithmetic number, because the mean of its divisors is an integer number (1084160).

Almost surely, 2^19901916 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 19901916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26019840).

19901916 is an abundant number, since it is smaller than the sum of its proper divisors (32137764).

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

19901916 is a wasteful number, since it uses less digits than its factorization.

19901916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1591 (or 1583 counting only the distinct ones).

The product of its (nonzero) digits is 4374, while the sum is 36.

The square root of 19901916 is about 4461.1563523374. The cubic root of 19901916 is about 270.9972993926.

The spelling of 19901916 in words is "nineteen million, nine hundred one thousand, nine hundred sixteen".