81453139 has 2 divisors, whose sum is σ = 81453140. Its totient is φ = 81453138.

The previous prime is 81453109. The next prime is 81453157. The reversal of 81453139 is 93135418.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81453139 is a prime.

It is a super-2 number, since 2×81453139² = 13269227705906642, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81453109) 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, 40726569 + 40726570.

It is an arithmetic number, because the mean of its divisors is an integer number (40726570).

Almost surely, 2^81453139 is an apocalyptic number.

81453139 is a deficient number, since it is larger than the sum of its proper divisors (1).

81453139 is an equidigital number, since it uses as much as digits as its factorization.

81453139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 34.

The square root of 81453139 is about 9025.1392787037. The cubic root of 81453139 is about 433.4802101058.

The spelling of 81453139 in words is "eighty-one million, four hundred fifty-three thousand, one hundred thirty-nine".