82409561 has 16 divisors (see below), whose sum is σ = 93004800. Its totient is φ = 72491328.

The previous prime is 82409533. The next prime is 82409573. The reversal of 82409561 is 16590428.

It is not a de Polignac number, because 82409561 - 2⁶ = 82409497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82409861) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28400 + ... + 31166.

It is an arithmetic number, because the mean of its divisors is an integer number (5812800).

Almost surely, 2^82409561 is an apocalyptic number.

It is an amenable number.

82409561 is a deficient number, since it is larger than the sum of its proper divisors (10595239).

82409561 is a wasteful number, since it uses less digits than its factorization.

82409561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2888.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 82409561 is about 9077.9711940499. The cubic root of 82409561 is about 435.1702526417.

Adding to 82409561 its reverse (16590428), we get a palindrome (98999989).

The spelling of 82409561 in words is "eighty-two million, four hundred nine thousand, five hundred sixty-one".