1663898409 has 16 divisors (see below), whose sum is σ = 2610037440. Its totient is φ = 1044014400.

The previous prime is 1663898393. The next prime is 1663898437. The reversal of 1663898409 is 9048983661.

It is not a de Polignac number, because 1663898409 - 2⁴ = 1663898393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1663898009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1812067 + ... + 1812984.

It is an arithmetic number, because the mean of its divisors is an integer number (163127340).

Almost surely, 2^1663898409 is an apocalyptic number.

It is an amenable number.

1663898409 is a deficient number, since it is larger than the sum of its proper divisors (946139031).

1663898409 is a wasteful number, since it uses less digits than its factorization.

1663898409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3625077 (or 3625071 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 54.

The square root of 1663898409 is about 40790.9108625929. The cubic root of 1663898409 is about 1184.9743112521.

The spelling of 1663898409 in words is "one billion, six hundred sixty-three million, eight hundred ninety-eight thousand, four hundred nine".