81269285 has 4 divisors (see below), whose sum is σ = 97523148. Its totient is φ = 65015424.

The previous prime is 81269273. The next prime is 81269303. The reversal of 81269285 is 58296218.

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 56806369 + 24462916 = 7537^2 + 4946^2 .

It is a cyclic number.

It is not a de Polignac number, because 81269285 - 2¹⁴ = 81252901 is a prime.

It is a super-2 number, since 2×81269285² = 13209393368822450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8126924 + ... + 8126933.

It is an arithmetic number, because the mean of its divisors is an integer number (24380787).

Almost surely, 2^81269285 is an apocalyptic number.

It is an amenable number.

81269285 is a deficient number, since it is larger than the sum of its proper divisors (16253863).

81269285 is a wasteful number, since it uses less digits than its factorization.

81269285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16253862.

The product of its digits is 69120, while the sum is 41.

The square root of 81269285 is about 9014.9478645192. The cubic root of 81269285 is about 433.1538174902.

The spelling of 81269285 in words is "eighty-one million, two hundred sixty-nine thousand, two hundred eighty-five".