20021009997 has 16 divisors (see below), whose sum is σ = 27352080000. Its totient is φ = 13018790400.

The previous prime is 20021009923. The next prime is 20021009999. The reversal of 20021009997 is 79990012002.

It is a happy number.

It is not a de Polignac number, because 20021009997 - 2⁸ = 20021009741 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021009999) 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 15 ways as a sum of consecutive naturals, for example, 598597 + ... + 631157.

It is an arithmetic number, because the mean of its divisors is an integer number (1709505000).

Almost surely, 2^20021009997 is an apocalyptic number.

It is an amenable number.

20021009997 is a deficient number, since it is larger than the sum of its proper divisors (7331070003).

20021009997 is a wasteful number, since it uses less digits than its factorization.

20021009997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37604.

The product of its (nonzero) digits is 20412, while the sum is 39.

The spelling of 20021009997 in words is "twenty billion, twenty-one million, nine thousand, nine hundred ninety-seven".