20817633868240 has 40 divisors (see below), whose sum is σ = 52801089540768. Its totient is φ = 7570048679040.

The previous prime is 20817633868237. The next prime is 20817633868313. The reversal of 20817633868240 is 4286833671802.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11828200182 + ... + 11828201941.

Almost surely, 2^{20817633868240} is an apocalyptic number.

20817633868240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20817633868240 is an abundant number, since it is smaller than the sum of its proper divisors (31983455672528).

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

20817633868240 is a wasteful number, since it uses less digits than its factorization.

20817633868240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23656402147 (or 23656402141 counting only the distinct ones).

The product of its (nonzero) digits is 18579456, while the sum is 58.

The spelling of 20817633868240 in words is "twenty trillion, eight hundred seventeen billion, six hundred thirty-three million, eight hundred sixty-eight thousand, two hundred forty".