82561551 has 4 divisors (see below), whose sum is σ = 110082072. Its totient is φ = 55041032.

The previous prime is 82561547. The next prime is 82561553. The reversal of 82561551 is 15516528.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 82561551 - 2² = 82561547 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82561553) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13760256 + ... + 13760261.

It is an arithmetic number, because the mean of its divisors is an integer number (27520518).

Almost surely, 2^82561551 is an apocalyptic number.

82561551 is a deficient number, since it is larger than the sum of its proper divisors (27520521).

82561551 is a wasteful number, since it uses less digits than its factorization.

82561551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27520520.

The product of its digits is 12000, while the sum is 33.

The square root of 82561551 is about 9086.3387015893. The cubic root of 82561551 is about 435.4376201063.

The spelling of 82561551 in words is "eighty-two million, five hundred sixty-one thousand, five hundred fifty-one".