81265801 has 16 divisors (see below), whose sum is σ = 88030800. Its totient is φ = 74850048.

The previous prime is 81265783. The next prime is 81265817. The reversal of 81265801 is 10856218.

It can be written as a sum of positive squares in 8 ways, for example, as 697225 + 80568576 = 835^2 + 8976^2 .

It is a cyclic number.

It is not a de Polignac number, because 81265801 - 2⁷ = 81265673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81265861) 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, 56155 + ... + 57583.

It is an arithmetic number, because the mean of its divisors is an integer number (5501925).

Almost surely, 2^81265801 is an apocalyptic number.

It is an amenable number.

81265801 is a deficient number, since it is larger than the sum of its proper divisors (6764999).

81265801 is a wasteful number, since it uses less digits than its factorization.

81265801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1548.

The product of its (nonzero) digits is 3840, while the sum is 31.

The square root of 81265801 is about 9014.7546278310. The cubic root of 81265801 is about 433.1476276590.

The spelling of 81265801 in words is "eighty-one million, two hundred sixty-five thousand, eight hundred one".