81437339 has 2 divisors, whose sum is σ = 81437340. Its totient is φ = 81437338.

The previous prime is 81437311. The next prime is 81437351. The reversal of 81437339 is 93373418.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81437339 is a prime.

It is not a weakly prime, because it can be changed into another prime (81437039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40718669 + 40718670.

It is an arithmetic number, because the mean of its divisors is an integer number (40718670).

Almost surely, 2^81437339 is an apocalyptic number.

81437339 is a deficient number, since it is larger than the sum of its proper divisors (1).

81437339 is an equidigital number, since it uses as much as digits as its factorization.

81437339 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 38.

The square root of 81437339 is about 9024.2639034993. The cubic root of 81437339 is about 433.4521799595.

The spelling of 81437339 in words is "eighty-one million, four hundred thirty-seven thousand, three hundred thirty-nine".