81545951 has 2 divisors, whose sum is σ = 81545952. Its totient is φ = 81545950.

The previous prime is 81545927. The next prime is 81545953. The reversal of 81545951 is 15954518.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81545951 - 2⁶ = 81545887 is a prime.

Together with 81545953, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81545953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40772975 + 40772976.

It is an arithmetic number, because the mean of its divisors is an integer number (40772976).

Almost surely, 2^81545951 is an apocalyptic number.

81545951 is a deficient number, since it is larger than the sum of its proper divisors (1).

81545951 is an equidigital number, since it uses as much as digits as its factorization.

81545951 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36000, while the sum is 38.

The square root of 81545951 is about 9030.2796745173. The cubic root of 81545951 is about 433.6447910110.

The spelling of 81545951 in words is "eighty-one million, five hundred forty-five thousand, nine hundred fifty-one".