1663633920 has 320 divisors, whose sum is σ = 6035863680. Its totient is φ = 387514368.

The previous prime is 1663633897. The next prime is 1663633927. The reversal of 1663633920 is 293363661.

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (1663633927) 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, 1896522 + ... + 1897398.

It is an arithmetic number, because the mean of its divisors is an integer number (18862074).

Almost surely, 2^1663633920 is an apocalyptic number.

1663633920 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 1663633920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3017931840).

1663633920 is an abundant number, since it is smaller than the sum of its proper divisors (4372229760).

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

1663633920 is a wasteful number, since it uses less digits than its factorization.

1663633920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 935 (or 919 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 39.

The square root of 1663633920 is about 40787.6687247506. The cubic root of 1663633920 is about 1184.9115211048.

The spelling of 1663633920 in words is "one billion, six hundred sixty-three million, six hundred thirty-three thousand, nine hundred twenty".