81980033 has 4 divisors (see below), whose sum is σ = 83979588. Its totient is φ = 79980480.

The previous prime is 81980011. The next prime is 81980047. The reversal of 81980033 is 33008918.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1555009 + 80425024 = 1247^2 + 8968^2 .

It is a cyclic number.

It is not a de Polignac number, because 81980033 - 2²⁶ = 14871169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81980233) 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, 999716 + ... + 999797.

It is an arithmetic number, because the mean of its divisors is an integer number (20994897).

Almost surely, 2^81980033 is an apocalyptic number.

It is an amenable number.

81980033 is a deficient number, since it is larger than the sum of its proper divisors (1999555).

81980033 is a wasteful number, since it uses less digits than its factorization.

81980033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1999554.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 81980033 is about 9054.2825778744. The cubic root of 81980033 is about 434.4128830063.

The spelling of 81980033 in words is "eighty-one million, nine hundred eighty thousand, thirty-three".