81155424 has 48 divisors (see below), whose sum is σ = 243468288. Its totient is φ = 23187072.

The previous prime is 81155423. The next prime is 81155443. The reversal of 81155424 is 42455118.

It is a tau number, because it is divible by the number of its divisors (48).

It is a junction number, because it is equal to n+sod(n) for n = 81155391 and 81155400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81155423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59712 + ... + 61055.

It is an arithmetic number, because the mean of its divisors is an integer number (5072256).

Almost surely, 2^81155424 is an apocalyptic number.

81155424 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

81155424 is an abundant number, since it is smaller than the sum of its proper divisors (162312864).

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

81155424 is a wasteful number, since it uses less digits than its factorization.

81155424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120787 (or 120779 counting only the distinct ones).

The product of its digits is 6400, while the sum is 30.

The square root of 81155424 is about 9008.6305285543. The cubic root of 81155424 is about 432.9514352600.

The spelling of 81155424 in words is "eighty-one million, one hundred fifty-five thousand, four hundred twenty-four".