81925279 has 2 divisors, whose sum is σ = 81925280. Its totient is φ = 81925278.

The previous prime is 81925247. The next prime is 81925303. The reversal of 81925279 is 97252918.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81925279 - 2⁵ = 81925247 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81925579) 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, 40962639 + 40962640.

It is an arithmetic number, because the mean of its divisors is an integer number (40962640).

Almost surely, 2^81925279 is an apocalyptic number.

81925279 is a deficient number, since it is larger than the sum of its proper divisors (1).

81925279 is an equidigital number, since it uses as much as digits as its factorization.

81925279 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 43.

The square root of 81925279 is about 9051.2584207943. The cubic root of 81925279 is about 434.3161474982.

The spelling of 81925279 in words is "eighty-one million, nine hundred twenty-five thousand, two hundred seventy-nine".