81820269 has 24 divisors (see below), whose sum is σ = 130583232. Its totient is φ = 49104000.

The previous prime is 81820259. The next prime is 81820309. The reversal of 81820269 is 96202818.

It is not a de Polignac number, because 81820269 - 2⁵ = 81820237 is a prime.

It is a super-2 number, since 2×81820269² = 13389112838464722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81820229) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8107 + ... + 15144.

It is an arithmetic number, because the mean of its divisors is an integer number (5440968).

Almost surely, 2^81820269 is an apocalyptic number.

It is an amenable number.

81820269 is a deficient number, since it is larger than the sum of its proper divisors (48762963).

81820269 is a wasteful number, since it uses less digits than its factorization.

81820269 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23297 (or 23294 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 81820269 is about 9045.4557099131. The cubic root of 81820269 is about 434.1305025652.

The spelling of 81820269 in words is "eighty-one million, eight hundred twenty thousand, two hundred sixty-nine".