81266031 has 32 divisors (see below), whose sum is σ = 150105600. Its totient is φ = 42215040.

The previous prime is 81266027. The next prime is 81266039. The reversal of 81266031 is 13066218.

It is not a de Polignac number, because 81266031 - 2² = 81266027 is a prime.

It is a super-2 number, since 2×81266031² = 13208335588985922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 81265986 and 81266004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81266039) 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 31 ways as a sum of consecutive naturals, for example, 17466 + ... + 21623.

It is an arithmetic number, because the mean of its divisors is an integer number (4690800).

Almost surely, 2^81266031 is an apocalyptic number.

81266031 is a deficient number, since it is larger than the sum of its proper divisors (68839569).

81266031 is a wasteful number, since it uses less digits than its factorization.

81266031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39116 (or 39110 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 81266031 is about 9014.7673846861. The cubic root of 81266031 is about 433.1480362928.

The spelling of 81266031 in words is "eighty-one million, two hundred sixty-six thousand, thirty-one".