82649561 has 2 divisors, whose sum is σ = 82649562. Its totient is φ = 82649560.

The previous prime is 82649549. The next prime is 82649579. The reversal of 82649561 is 16594628.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81793936 + 855625 = 9044^2 + 925^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-82649561 is a prime.

It is not a weakly prime, because it can be changed into another prime (82609561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41324780 + 41324781.

It is an arithmetic number, because the mean of its divisors is an integer number (41324781).

Almost surely, 2^82649561 is an apocalyptic number.

It is an amenable number.

82649561 is a deficient number, since it is larger than the sum of its proper divisors (1).

82649561 is an equidigital number, since it uses as much as digits as its factorization.

82649561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 41.

The square root of 82649561 is about 9091.1803964062. The cubic root of 82649561 is about 435.5922895832.

The spelling of 82649561 in words is "eighty-two million, six hundred forty-nine thousand, five hundred sixty-one".