20171399220 has 480 divisors, whose sum is σ = 74312663040. Its totient is φ = 4485507840.

The previous prime is 20171399197. The next prime is 20171399221. The reversal of 20171399220 is 2299317102.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20171399221) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 105609325 + ... + 105609515.

It is an arithmetic number, because the mean of its divisors is an integer number (154818048).

Almost surely, 2^20171399220 is an apocalyptic number.

20171399220 is a gapful number since it is divisible by the number (20) 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 20171399220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37156331520).

20171399220 is an abundant number, since it is smaller than the sum of its proper divisors (54141263820).

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

20171399220 is a wasteful number, since it uses less digits than its factorization.

20171399220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425 (or 414 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The spelling of 20171399220 in words is "twenty billion, one hundred seventy-one million, three hundred ninety-nine thousand, two hundred twenty".