81909162 has 24 divisors (see below), whose sum is σ = 187909956. Its totient is φ = 25696896.

The previous prime is 81909151. The next prime is 81909173. The reversal of 81909162 is 26190918.

It is an interprime number because it is at equal distance from previous prime (81909151) and next prime (81909173).

It can be written as a sum of positive squares in 2 ways, for example, as 67914081 + 13995081 = 8241^2 + 3741^2 .

It is a super-2 number, since 2×81909162² = 13418221639084488, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 133533 + ... + 134144.

Almost surely, 2^81909162 is an apocalyptic number.

81909162 is an abundant number, since it is smaller than the sum of its proper divisors (106000794).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81909162 is a wasteful number, since it uses less digits than its factorization.

81909162 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267702 (or 267699 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 81909162 is about 9050.3680588140. The cubic root of 81909162 is about 434.2876649081.

It can be divided in two parts, 8190916 and 2, that added together give a palindrome (8190918).

The spelling of 81909162 in words is "eighty-one million, nine hundred nine thousand, one hundred sixty-two".