1663123220 has 54 divisors (see below), whose sum is σ = 3843564606. Its totient is φ = 604042560.

The previous prime is 1663123213. The next prime is 1663123223. The reversal of 1663123220 is 223213661.

It can be written as a sum of positive squares in 3 ways, for example, as 249513616 + 1413609604 = 15796^2 + 37598^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1663123220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663123223) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2005766 + ... + 2006594.

Almost surely, 2^1663123220 is an apocalyptic number.

1663123220 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 1663123220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1921782303).

1663123220 is an abundant number, since it is smaller than the sum of its proper divisors (2180441386).

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

1663123220 is an equidigital number, since it uses as much as digits as its factorization.

1663123220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1689 (or 847 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 1663123220 is about 40781.4077736412. The cubic root of 1663123220 is about 1184.7902612054.

Adding to 1663123220 its reverse (223213661), we get a palindrome (1886336881).

The spelling of 1663123220 in words is "one billion, six hundred sixty-three million, one hundred twenty-three thousand, two hundred twenty".