81575051 has 2 divisors, whose sum is σ = 81575052. Its totient is φ = 81575050.

The previous prime is 81574943. The next prime is 81575059. The reversal of 81575051 is 15057518.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81575051 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 81574999 and 81575017.

It is not a weakly prime, because it can be changed into another prime (81575059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40787525 + 40787526.

It is an arithmetic number, because the mean of its divisors is an integer number (40787526).

Almost surely, 2^81575051 is an apocalyptic number.

81575051 is a deficient number, since it is larger than the sum of its proper divisors (1).

81575051 is an equidigital number, since it uses as much as digits as its factorization.

81575051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7000, while the sum is 32.

The square root of 81575051 is about 9031.8907765761. The cubic root of 81575051 is about 433.6963675046.

The spelling of 81575051 in words is "eighty-one million, five hundred seventy-five thousand, fifty-one".