19909764 has 108 divisors (see below), whose sum is σ = 60208512. Its totient is φ = 5431680.

The previous prime is 19909763. The next prime is 19909793. The reversal of 19909764 is 46790991.

It is not an unprimeable number, because it can be changed into a prime (19909763) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 423589 + ... + 423635.

Almost surely, 2^19909764 is an apocalyptic number.

19909764 is a gapful number since it is divisible by the number (14) 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 19909764, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30104256).

19909764 is an abundant number, since it is smaller than the sum of its proper divisors (40298748).

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

19909764 is a wasteful number, since it uses less digits than its factorization.

19909764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 100 counting only the distinct ones).

The product of its (nonzero) digits is 122472, while the sum is 45.

The square root of 19909764 is about 4462.0358582154. The cubic root of 19909764 is about 271.0329158513.

The spelling of 19909764 in words is "nineteen million, nine hundred nine thousand, seven hundred sixty-four".