81953587 has 2 divisors, whose sum is σ = 81953588. Its totient is φ = 81953586.

The previous prime is 81953567. The next prime is 81953591. The reversal of 81953587 is 78535918.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81953587 is a prime.

It is not a weakly prime, because it can be changed into another prime (81953567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40976793 + 40976794.

It is an arithmetic number, because the mean of its divisors is an integer number (40976794).

Almost surely, 2^81953587 is an apocalyptic number.

81953587 is a deficient number, since it is larger than the sum of its proper divisors (1).

81953587 is an equidigital number, since it uses as much as digits as its factorization.

81953587 is an evil number, because the sum of its binary digits is even.

The product of its digits is 302400, while the sum is 46.

The square root of 81953587 is about 9052.8220461909. The cubic root of 81953587 is about 434.3661654570.

The spelling of 81953587 in words is "eighty-one million, nine hundred fifty-three thousand, five hundred eighty-seven".