220401720 has 192 divisors, whose sum is σ = 893168640. Its totient is φ = 45792000.

The previous prime is 220401697. The next prime is 220401733. The reversal of 220401720 is 27104022.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 220401693 and 220401702.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 23745 + ... + 31695.

It is an arithmetic number, because the mean of its divisors is an integer number (4651920).

Almost surely, 2^220401720 is an apocalyptic number.

220401720 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 220401720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (446584320).

220401720 is an abundant number, since it is smaller than the sum of its proper divisors (672766920).

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

220401720 is a wasteful number, since it uses less digits than its factorization.

220401720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7986 (or 7979 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 18.

The square root of 220401720 is about 14845.9327763533. The cubic root of 220401720 is about 604.0482908044.

Adding to 220401720 its reverse (27104022), we get a palindrome (247505742).

The spelling of 220401720 in words is "two hundred twenty million, four hundred one thousand, seven hundred twenty".