20332981 has 2 divisors, whose sum is σ = 20332982. Its totient is φ = 20332980.

The previous prime is 20332979. The next prime is 20333009. The reversal of 20332981 is 18923302.

It is an a-pointer prime, because the next prime (20333009) can be obtained adding 20332981 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16851025 + 3481956 = 4105^2 + 1866^2 .

It is a cyclic number.

It is not a de Polignac number, because 20332981 - 2¹ = 20332979 is a prime.

It is a super-2 number, since 2×20332981² = 826860232692722, which contains 22 as substring.

Together with 20332979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20332951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10166490 + 10166491.

It is an arithmetic number, because the mean of its divisors is an integer number (10166491).

Almost surely, 2^20332981 is an apocalyptic number.

It is an amenable number.

20332981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20332981 is an equidigital number, since it uses as much as digits as its factorization.

20332981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 20332981 is about 4509.2106848095. The cubic root of 20332981 is about 272.9398938282.

The spelling of 20332981 in words is "twenty million, three hundred thirty-two thousand, nine hundred eighty-one".