19640740 has 48 divisors (see below), whose sum is σ = 48045312. Its totient is φ = 6604416.

The previous prime is 19640713. The next prime is 19640741. The reversal of 19640740 is 4704691.

It is not an unprimeable number, because it can be changed into a prime (19640741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6097 + ... + 8743.

It is an arithmetic number, because the mean of its divisors is an integer number (1000944).

Almost surely, 2^19640740 is an apocalyptic number.

19640740 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 19640740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24022656).

19640740 is an abundant number, since it is smaller than the sum of its proper divisors (28404572).

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

19640740 is a wasteful number, since it uses less digits than its factorization.

19640740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2716 (or 2714 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 19640740 is about 4431.7874497769. The cubic root of 19640740 is about 269.8066288037.

The spelling of 19640740 in words is "nineteen million, six hundred forty thousand, seven hundred forty".