81592417 has 2 divisors, whose sum is σ = 81592418. Its totient is φ = 81592416.

The previous prime is 81592373. The next prime is 81592451. The reversal of 81592417 is 71429518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81162081 + 430336 = 9009^2 + 656^2 .

It is a cyclic number.

It is not a de Polignac number, because 81592417 - 2¹⁹ = 81068129 is a prime.

It is not a weakly prime, because it can be changed into another prime (81592117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40796208 + 40796209.

It is an arithmetic number, because the mean of its divisors is an integer number (40796209).

Almost surely, 2^81592417 is an apocalyptic number.

It is an amenable number.

81592417 is a deficient number, since it is larger than the sum of its proper divisors (1).

81592417 is an equidigital number, since it uses as much as digits as its factorization.

81592417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 37.

The square root of 81592417 is about 9032.8520966525. The cubic root of 81592417 is about 433.7271409525.

The spelling of 81592417 in words is "eighty-one million, five hundred ninety-two thousand, four hundred seventeen".