20021021331331 has 4 divisors (see below), whose sum is σ = 20215400179312. Its totient is φ = 19826642483352.

The previous prime is 20021021331317. The next prime is 20021021331343. The reversal of 20021021331331 is 13313312012002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20021021331331 - 2³⁷ = 19883582377859 is a prime.

It is a super-2 number, since 2×20021021331331² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20021021334331) 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, 97189423836 + ... + 97189424041.

It is an arithmetic number, because the mean of its divisors is an integer number (5053850044828).

Almost surely, 2^{20021021331331} is an apocalyptic number.

20021021331331 is a deficient number, since it is larger than the sum of its proper divisors (194378847981).

20021021331331 is a wasteful number, since it uses less digits than its factorization.

20021021331331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194378847980.

The product of its (nonzero) digits is 648, while the sum is 22.

Adding to 20021021331331 its reverse (13313312012002), we get a palindrome (33334333343333).

The spelling of 20021021331331 in words is "twenty trillion, twenty-one billion, twenty-one million, three hundred thirty-one thousand, three hundred thirty-one".