18331100020021 has 8 divisors (see below), whose sum is σ = 18394365367224. Its totient is φ = 18267839448000.

The previous prime is 18331100020003. The next prime is 18331100020027. The reversal of 18331100020021 is 12002000113381.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3887261764996 + 14443838255025 = 1971614^2 + 3800505^2 .

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 18331100020021 - 2²⁵ = 18331066465589 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18331100019974 and 18331100020001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18331100020027) 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, 6584395 + ... + 8945191.

It is an arithmetic number, because the mean of its divisors is an integer number (2299295670903).

Almost surely, 2^{18331100020021} is an apocalyptic number.

It is an amenable number.

18331100020021 is a deficient number, since it is larger than the sum of its proper divisors (63265347203).

18331100020021 is a wasteful number, since it uses less digits than its factorization.

18331100020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2387591.

The product of its (nonzero) digits is 288, while the sum is 22.

The spelling of 18331100020021 in words is "eighteen trillion, three hundred thirty-one billion, one hundred million, twenty thousand, twenty-one".