80812021 has 4 divisors (see below), whose sum is σ = 80919532. Its totient is φ = 80704512.

The previous prime is 80812013. The next prime is 80812051. The reversal of 80812021 is 12021808.

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 52403121 + 28408900 = 7239^2 + 5330^2 .

It is a cyclic number.

It is not a de Polignac number, because 80812021 - 2³ = 80812013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 80811983 and 80812001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80812001) 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, 52620 + ... + 54133.

It is an arithmetic number, because the mean of its divisors is an integer number (20229883).

Almost surely, 2^80812021 is an apocalyptic number.

It is an amenable number.

80812021 is a deficient number, since it is larger than the sum of its proper divisors (107511).

80812021 is a wasteful number, since it uses less digits than its factorization.

80812021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107510.

The product of its (nonzero) digits is 256, while the sum is 22.

The square root of 80812021 is about 8989.5506561785. The cubic root of 80812021 is about 432.3399048835.

Adding to 80812021 its reverse (12021808), we get a palindrome (92833829).

The spelling of 80812021 in words is "eighty million, eight hundred twelve thousand, twenty-one".