80817021 has 10 divisors (see below), whose sum is σ = 120726782. Its totient is φ = 53877960.

The previous prime is 80816987. The next prime is 80817029. The reversal of 80817021 is 12071808.

It can be written as a sum of positive squares in only one way, i.e., 46172025 + 34644996 = 6795^2 + 5886^2 .

It is not a de Polignac number, because 80817021 - 2⁹ = 80816509 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80817029) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 498790 + ... + 498951.

Almost surely, 2^80817021 is an apocalyptic number.

80817021 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

It is an amenable number.

80817021 is a deficient number, since it is larger than the sum of its proper divisors (39909761).

80817021 is an equidigital number, since it uses as much as digits as its factorization.

80817021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 997753 (or 997744 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 80817021 is about 8989.8287525403. The cubic root of 80817021 is about 432.3488212754.

Adding to 80817021 its reverse (12071808), we get a palindrome (92888829).

The spelling of 80817021 in words is "eighty million, eight hundred seventeen thousand, twenty-one".