81802969 has 4 divisors (see below), whose sum is σ = 83189520. Its totient is φ = 80416420.

The previous prime is 81802951. The next prime is 81802979. The reversal of 81802969 is 96920818.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81802969 - 2¹⁵ = 81770201 is a prime.

It is a super-2 number, since 2×81802969² = 13383451474429922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81802949) 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 3 ways as a sum of consecutive naturals, for example, 693187 + ... + 693304.

It is an arithmetic number, because the mean of its divisors is an integer number (20797380).

Almost surely, 2^81802969 is an apocalyptic number.

It is an amenable number.

81802969 is a deficient number, since it is larger than the sum of its proper divisors (1386551).

81802969 is a wasteful number, since it uses less digits than its factorization.

81802969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1386550.

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 81802969 is about 9044.4993780751. The cubic root of 81802969 is about 434.0999030280.

The spelling of 81802969 in words is "eighty-one million, eight hundred two thousand, nine hundred sixty-nine".