20201021210999 has 16 divisors (see below), whose sum is σ = 20476043758080. Its totient is φ = 19927753401600.

The previous prime is 20201021210971. The next prime is 20201021211017. The reversal of 20201021210999 is 99901212010202.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20201021210999 - 2⁸ = 20201021210743 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20201021210599) 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, 26785424 + ... + 27529274.

It is an arithmetic number, because the mean of its divisors is an integer number (1279752734880).

Almost surely, 2^{20201021210999} is an apocalyptic number.

20201021210999 is a deficient number, since it is larger than the sum of its proper divisors (275022547081).

20201021210999 is a wasteful number, since it uses less digits than its factorization.

20201021210999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 745030.

The product of its (nonzero) digits is 11664, while the sum is 38.

The spelling of 20201021210999 in words is "twenty trillion, two hundred one billion, twenty-one million, two hundred ten thousand, nine hundred ninety-nine".