20817826380 has 72 divisors (see below), whose sum is σ = 68004907152. Its totient is φ = 5124387456.

The previous prime is 20817826343. The next prime is 20817826511. The reversal of 20817826380 is 8362871802.

20817826380 is a `hidden beast` number, since 2 + 0 + 8 + 1 + 7 + 8 + 2 + 638 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4445914 + ... + 4450593.

Almost surely, 2^20817826380 is an apocalyptic number.

20817826380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20817826380 is an abundant number, since it is smaller than the sum of its proper divisors (47187080772).

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

20817826380 is a wasteful number, since it uses less digits than its factorization.

20817826380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8896535 (or 8896530 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 45.

The spelling of 20817826380 in words is "twenty billion, eight hundred seventeen million, eight hundred twenty-six thousand, three hundred eighty".