1663990720 has 168 divisors, whose sum is σ = 4685275872. Its totient is φ = 551393280.

The previous prime is 1663990717. The next prime is 1663990789. The reversal of 1663990720 is 270993661.

It is a super-2 number, since 2×1663990720² = 5537730232492236800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2152254 + ... + 2153026.

Almost surely, 2^1663990720 is an apocalyptic number.

1663990720 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 1663990720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2342637936).

1663990720 is an abundant number, since it is smaller than the sum of its proper divisors (3021285152).

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

1663990720 is an equidigital number, since it uses as much as digits as its factorization.

1663990720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 859 (or 818 counting only the distinct ones).

The product of its (nonzero) digits is 122472, while the sum is 43.

The square root of 1663990720 is about 40792.0423612253. The cubic root of 1663990720 is about 1184.9962244772.

The spelling of 1663990720 in words is "one billion, six hundred sixty-three million, nine hundred ninety thousand, seven hundred twenty".