81435120 has 160 divisors (see below), whose sum is σ = 278648832. Its totient is φ = 19547136.

The previous prime is 81435119. The next prime is 81435139. The reversal of 81435120 is 2153418.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 133857 + ... + 134463.

Almost surely, 2^81435120 is an apocalyptic number.

81435120 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81435120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139324416).

81435120 is an abundant number, since it is smaller than the sum of its proper divisors (197213712).

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

81435120 is a wasteful number, since it uses less digits than its factorization.

81435120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679 (or 673 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 81435120 is about 9024.1409563459. The cubic root of 81435120 is about 433.4482430303.

Adding to 81435120 its reverse (2153418), we get a palindrome (83588538).

The spelling of 81435120 in words is "eighty-one million, four hundred thirty-five thousand, one hundred twenty".