81953471 has 2 divisors, whose sum is σ = 81953472. Its totient is φ = 81953470.

The previous prime is 81953461. The next prime is 81953513. The reversal of 81953471 is 17435918.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81953471 - 2¹⁸ = 81691327 is a prime.

It is a super-3 number, since 3×81953471³ (a number of 25 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81953411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40976735 + 40976736.

It is an arithmetic number, because the mean of its divisors is an integer number (40976736).

Almost surely, 2^81953471 is an apocalyptic number.

81953471 is a deficient number, since it is larger than the sum of its proper divisors (1).

81953471 is an equidigital number, since it uses as much as digits as its factorization.

81953471 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 38.

The square root of 81953471 is about 9052.8156393467. The cubic root of 81953471 is about 434.3659605179.

The spelling of 81953471 in words is "eighty-one million, nine hundred fifty-three thousand, four hundred seventy-one".