81406120 has 32 divisors (see below), whose sum is σ = 183436200. Its totient is φ = 32514048.

The previous prime is 81406109. The next prime is 81406159. The reversal of 81406120 is 2160418.

It can be written as a sum of positive squares in 4 ways, for example, as 70660836 + 10745284 = 8406^2 + 3278^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81406091 and 81406100.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39352 + ... + 41368.

Almost surely, 2^81406120 is an apocalyptic number.

It is an amenable number.

81406120 is an abundant number, since it is smaller than the sum of its proper divisors (102030080).

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

81406120 is a wasteful number, since it uses less digits than its factorization.

81406120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3037 (or 3033 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 81406120 is about 9022.5340121276. The cubic root of 81406120 is about 433.3967849229.

Adding to 81406120 its reverse (2160418), we get a palindrome (83566538).

The spelling of 81406120 in words is "eighty-one million, four hundred six thousand, one hundred twenty".