20716217490 has 64 divisors (see below), whose sum is σ = 51288246144. Its totient is φ = 5351275008.

The previous prime is 20716217447. The next prime is 20716217491. The reversal of 20716217490 is 9471261702.

It is not an unprimeable number, because it can be changed into a prime (20716217491) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 210862 + ... + 293078.

It is an arithmetic number, because the mean of its divisors is an integer number (801378846).

Almost surely, 2^20716217490 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20716217490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25644123072).

20716217490 is an abundant number, since it is smaller than the sum of its proper divisors (30572028654).

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

20716217490 is a wasteful number, since it uses less digits than its factorization.

20716217490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82491.

The product of its (nonzero) digits is 42336, while the sum is 39.

The spelling of 20716217490 in words is "twenty billion, seven hundred sixteen million, two hundred seventeen thousand, four hundred ninety".