20331081 has 21 divisors (see below), whose sum is σ = 30666301.
Its totient is φ = 13472892.
The previous prime is 20331079. The next prime is 20331107. The reversal of 20331081 is 18013302.
Multipling 20331081 by its product of nonzero digits (144), we get a square (2927675664 = 541082).
Adding to 20331081 its reverse (18013302), we get a palindrome (38344383).
The square root of 20331081 is 4509.
It is a perfect power (a square), and thus also a powerful number.
It is not a de Polignac number, because 20331081 - 21 = 20331079 is a prime.
It is a super-2 number, since 2×203310812 = 826705709257122, which contains 22 as substring.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (20331061) by changing a digit.
It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 121660 + ... + 121826.
Almost surely, 220331081 is an apocalyptic number.
20331081 is the 4509-th square number.
20331081 is the 2255-th centered octagonal number.
It is an amenable number.
20331081 is a deficient number, since it is larger than the sum of its proper divisors (10335220).
20331081 is an frugal number, since it uses more digits than its factorization.
20331081 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 352 (or 170 counting only the distinct ones).
The product of its (nonzero) digits is 144, while the sum is 18.
The cubic root of 20331081 is about 272.9313920096.
The spelling of 20331081 in words is "twenty million, three hundred thirty-one thousand, eighty-one".