20011997285 has 32 divisors (see below), whose sum is σ = 28931385600. Its totient is φ = 12981427200.

The previous prime is 20011997281. The next prime is 20011997311. The reversal of 20011997285 is 58279911002.

It is a happy number.

It is not a de Polignac number, because 20011997285 - 2² = 20011997281 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011997281) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 444701 + ... + 487629.

It is an arithmetic number, because the mean of its divisors is an integer number (904105800).

Almost surely, 2^20011997285 is an apocalyptic number.

It is an amenable number.

20011997285 is a deficient number, since it is larger than the sum of its proper divisors (8919388315).

20011997285 is a wasteful number, since it uses less digits than its factorization.

20011997285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43661.

The product of its (nonzero) digits is 90720, while the sum is 44.

The spelling of 20011997285 in words is "twenty billion, eleven million, nine hundred ninety-seven thousand, two hundred eighty-five".