20331552420581 has 2 divisors, whose sum is σ = 20331552420582. Its totient is φ = 20331552420580.

The previous prime is 20331552420539. The next prime is 20331552420709. The reversal of 20331552420581 is 18502425513302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17054909398081 + 3276643022500 = 4129759^2 + 1810150^2 .

It is a cyclic number.

It is not a de Polignac number, because 20331552420581 - 2³⁸ = 20056674513637 is a prime.

It is a super-2 number, since 2×20331552420581² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20331552420281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10165776210290 + 10165776210291.

It is an arithmetic number, because the mean of its divisors is an integer number (10165776210291).

Almost surely, 2^{20331552420581} is an apocalyptic number.

It is an amenable number.

20331552420581 is a deficient number, since it is larger than the sum of its proper divisors (1).

20331552420581 is an equidigital number, since it uses as much as digits as its factorization.

20331552420581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288000, while the sum is 41.

Adding to 20331552420581 its reverse (18502425513302), we get a palindrome (38833977933883).

The spelling of 20331552420581 in words is "twenty trillion, three hundred thirty-one billion, five hundred fifty-two million, four hundred twenty thousand, five hundred eighty-one".