20731166331821 has 8 divisors (see below), whose sum is σ = 22693004911584. Its totient is φ = 18782192267920.

The previous prime is 20731166331809. The next prime is 20731166331829. The reversal of 20731166331821 is 12813366113702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20731166331821 - 2²⁶ = 20731099222957 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 (20731166331829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3216125591 + ... + 3216132036.

It is an arithmetic number, because the mean of its divisors is an integer number (2836625613948).

Almost surely, 2^{20731166331821} is an apocalyptic number.

It is an amenable number.

20731166331821 is a deficient number, since it is larger than the sum of its proper divisors (1961838579763).

20731166331821 is a wasteful number, since it uses less digits than its factorization.

20731166331821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6432257931.

The product of its (nonzero) digits is 217728, while the sum is 44.

The spelling of 20731166331821 in words is "twenty trillion, seven hundred thirty-one billion, one hundred sixty-six million, three hundred thirty-one thousand, eight hundred twenty-one".