81457039 has 2 divisors, whose sum is σ = 81457040. Its totient is φ = 81457038.

The previous prime is 81457003. The next prime is 81457069. The reversal of 81457039 is 93075418.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81457039 - 2⁹ = 81456527 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81456989 and 81457007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81457069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40728519 + 40728520.

It is an arithmetic number, because the mean of its divisors is an integer number (40728520).

Almost surely, 2^81457039 is an apocalyptic number.

81457039 is a deficient number, since it is larger than the sum of its proper divisors (1).

81457039 is an equidigital number, since it uses as much as digits as its factorization.

81457039 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 81457039 is about 9025.3553392650. The cubic root of 81457039 is about 433.4871283816.

The spelling of 81457039 in words is "eighty-one million, four hundred fifty-seven thousand, thirty-nine".