81420969 has 8 divisors (see below), whose sum is σ = 124070080. Its totient is φ = 46526256.

The previous prime is 81420961. The next prime is 81420971. The reversal of 81420969 is 96902418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81420969 - 2³ = 81420961 is a prime.

It is a super-2 number, since 2×81420969² = 13258748385797922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81420961) 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 7 ways as a sum of consecutive naturals, for example, 1938574 + ... + 1938615.

It is an arithmetic number, because the mean of its divisors is an integer number (15508760).

Almost surely, 2^81420969 is an apocalyptic number.

It is an amenable number.

81420969 is a deficient number, since it is larger than the sum of its proper divisors (42649111).

81420969 is a wasteful number, since it uses less digits than its factorization.

81420969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3877199.

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 81420969 is about 9023.3568587306. The cubic root of 81420969 is about 433.4231347747.

The spelling of 81420969 in words is "eighty-one million, four hundred twenty thousand, nine hundred sixty-nine".