20432981 has 2 divisors, whose sum is σ = 20432982.
Its totient is φ = 20432980.
The previous prime is 20432977. The next prime is 20433013. The reversal of 20432981 is 18923402.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 16532356 + 3900625 = 4066^2 + 1975^2
It is a cyclic number.
It is not a de Polignac number, because 20432981 - 22 = 20432977 is a prime.
It is a super-2 number, since 2×204329812 = 835013425092722, which contains 22 as substring.
It is a Chen prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (20432081) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (13) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10216490 + 10216491.
It is an arithmetic number, because the mean of its divisors is an integer number (10216491).
Almost surely, 220432981 is an apocalyptic number.
It is an amenable number.
20432981 is a deficient number, since it is larger than the sum of its proper divisors (1).
20432981 is an equidigital number, since it uses as much as digits as its factorization.
20432981 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 3456, while the sum is 29.
The square root of 20432981 is about 4520.2854998329.
The cubic root of 20432981 is about 273.3866124905.
The spelling of 20432981 in words is "twenty million, four hundred thirty-two thousand, nine hundred eighty-one".