1663657400 has 144 divisors (see below), whose sum is σ = 4162735800. Its totient is φ = 618158080.

The previous prime is 1663657361. The next prime is 1663657421. The reversal of 1663657400 is 47563661.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 6184466 + ... + 6184734.

Almost surely, 2^1663657400 is an apocalyptic number.

1663657400 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 1663657400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2081367900).

1663657400 is an abundant number, since it is smaller than the sum of its proper divisors (2499078400).

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

1663657400 is a wasteful number, since it uses less digits than its factorization.

1663657400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426 (or 400 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 38.

The square root of 1663657400 is about 40787.9565558266. The cubic root of 1663657400 is about 1184.9170955667.

The spelling of 1663657400 in words is "one billion, six hundred sixty-three million, six hundred fifty-seven thousand, four hundred".