81577361 has 2 divisors, whose sum is σ = 81577362. Its totient is φ = 81577360.

The previous prime is 81577283. The next prime is 81577381. The reversal of 81577361 is 16377518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81450625 + 126736 = 9025^2 + 356^2 .

It is a cyclic number.

It is not a de Polignac number, because 81577361 - 2²⁶ = 14468497 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81577381) 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, 40788680 + 40788681.

It is an arithmetic number, because the mean of its divisors is an integer number (40788681).

Almost surely, 2^81577361 is an apocalyptic number.

It is an amenable number.

81577361 is a deficient number, since it is larger than the sum of its proper divisors (1).

81577361 is an equidigital number, since it uses as much as digits as its factorization.

81577361 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35280, while the sum is 38.

The square root of 81577361 is about 9032.0186558709. The cubic root of 81577361 is about 433.7004611956.

The spelling of 81577361 in words is "eighty-one million, five hundred seventy-seven thousand, three hundred sixty-one".