1663537740 has 96 divisors (see below), whose sum is σ = 4769694720. Its totient is φ = 433015296.

The previous prime is 1663537697. The next prime is 1663537763. The reversal of 1663537740 is 477353661.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1663537692 and 1663537701.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1745104 + ... + 1746056.

It is an arithmetic number, because the mean of its divisors is an integer number (49684320).

Almost surely, 2^1663537740 is an apocalyptic number.

1663537740 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 1663537740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2384847360).

1663537740 is an abundant number, since it is smaller than the sum of its proper divisors (3106156980).

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

1663537740 is a wasteful number, since it uses less digits than its factorization.

1663537740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1631 (or 1629 counting only the distinct ones).

The product of its (nonzero) digits is 317520, while the sum is 42.

The square root of 1663537740 is about 40786.4896748911. The cubic root of 1663537740 is about 1184.8886861560. Note that the first 3 decimals are identical.

The spelling of 1663537740 in words is "one billion, six hundred sixty-three million, five hundred thirty-seven thousand, seven hundred forty".