81960973 has 2 divisors, whose sum is σ = 81960974. Its totient is φ = 81960972.

The previous prime is 81960947. The next prime is 81961001. The reversal of 81960973 is 37906918.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51523684 + 30437289 = 7178^2 + 5517^2 .

It is a cyclic number.

It is not a de Polignac number, because 81960973 - 2¹³ = 81952781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81960913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40980486 + 40980487.

It is an arithmetic number, because the mean of its divisors is an integer number (40980487).

Almost surely, 2^81960973 is an apocalyptic number.

It is an amenable number.

81960973 is a deficient number, since it is larger than the sum of its proper divisors (1).

81960973 is an equidigital number, since it uses as much as digits as its factorization.

81960973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81648, while the sum is 43.

The square root of 81960973 is about 9053.2299760914. The cubic root of 81960973 is about 434.3792140302.

The spelling of 81960973 in words is "eighty-one million, nine hundred sixty thousand, nine hundred seventy-three".