2021823803981 has 4 divisors (see below), whose sum is σ = 2022201932352. Its totient is φ = 2021445675612.

The previous prime is 2021823803959. The next prime is 2021823804037. The reversal of 2021823803981 is 1893083281202.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2021823803981 - 2¹⁴ = 2021823787597 is a prime.

It is a super-2 number, since 2×2021823803981² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021823803381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 189056165 + ... + 189066858.

It is an arithmetic number, because the mean of its divisors is an integer number (505550483088).

Almost surely, 2^{2021823803981} is an apocalyptic number.

It is an amenable number.

2021823803981 is a deficient number, since it is larger than the sum of its proper divisors (378128371).

2021823803981 is an equidigital number, since it uses as much as digits as its factorization.

2021823803981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378128370.

The product of its (nonzero) digits is 331776, while the sum is 47.

The spelling of 2021823803981 in words is "two trillion, twenty-one billion, eight hundred twenty-three million, eight hundred three thousand, nine hundred eighty-one".