81020133 has 12 divisors (see below), whose sum is σ = 117194688. Its totient is φ = 53937000.

The previous prime is 81020131. The next prime is 81020179. The reversal of 81020133 is 33102018.

It is not a de Polignac number, because 81020133 - 2¹ = 81020131 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81020131) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 766 + ... + 12752.

It is an arithmetic number, because the mean of its divisors is an integer number (9766224).

Almost surely, 2^81020133 is an apocalyptic number.

It is an amenable number.

81020133 is a deficient number, since it is larger than the sum of its proper divisors (36174555).

81020133 is a wasteful number, since it uses less digits than its factorization.

81020133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12744 (or 12741 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 81020133 is about 9001.1184305063. The cubic root of 81020133 is about 432.7107160369.

The spelling of 81020133 in words is "eighty-one million, twenty thousand, one hundred thirty-three".