81298551 has 16 divisors (see below), whose sum is σ = 109790208. Its totient is φ = 53508000.

The previous prime is 81298541. The next prime is 81298559. The reversal of 81298551 is 15589218.

It is not a de Polignac number, because 81298551 - 2⁶ = 81298487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81298559) 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 in 15 ways as a sum of consecutive naturals, for example, 88786 + ... + 89696.

It is an arithmetic number, because the mean of its divisors is an integer number (6861888).

Almost surely, 2^81298551 is an apocalyptic number.

81298551 is a deficient number, since it is larger than the sum of its proper divisors (28491657).

81298551 is a wasteful number, since it uses less digits than its factorization.

81298551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1262.

The product of its digits is 28800, while the sum is 39.

The square root of 81298551 is about 9016.5709113831. The cubic root of 81298551 is about 433.2058057998.

The spelling of 81298551 in words is "eighty-one million, two hundred ninety-eight thousand, five hundred fifty-one".