81262751 has 4 divisors (see below), whose sum is σ = 81358872. Its totient is φ = 81166632.

The previous prime is 81262747. The next prime is 81262757. The reversal of 81262751 is 15726218.

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 81262751 - 2² = 81262747 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81262757) 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, 46781 + ... + 48486.

It is an arithmetic number, because the mean of its divisors is an integer number (20339718).

Almost surely, 2^81262751 is an apocalyptic number.

81262751 is a deficient number, since it is larger than the sum of its proper divisors (96121).

81262751 is an equidigital number, since it uses as much as digits as its factorization.

81262751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96120.

The product of its digits is 6720, while the sum is 32.

The square root of 81262751 is about 9014.5854591323. The cubic root of 81262751 is about 433.1422087465.

Adding to 81262751 its reverse (15726218), we get a palindrome (96988969).

The spelling of 81262751 in words is "eighty-one million, two hundred sixty-two thousand, seven hundred fifty-one".