81400337 has 2 divisors, whose sum is σ = 81400338. Its totient is φ = 81400336.

The previous prime is 81400307. The next prime is 81400343. The reversal of 81400337 is 73300418.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56490256 + 24910081 = 7516^2 + 4991^2 .

It is a cyclic number.

It is not a de Polignac number, because 81400337 - 2⁶ = 81400273 is a prime.

It is not a weakly prime, because it can be changed into another prime (81400307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40700168 + 40700169.

It is an arithmetic number, because the mean of its divisors is an integer number (40700169).

Almost surely, 2^81400337 is an apocalyptic number.

It is an amenable number.

81400337 is a deficient number, since it is larger than the sum of its proper divisors (1).

81400337 is an equidigital number, since it uses as much as digits as its factorization.

81400337 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 81400337 is about 9022.2135310577. The cubic root of 81400337 is about 433.3865220051.

The spelling of 81400337 in words is "eighty-one million, four hundred thousand, three hundred thirty-seven".