81047424 has 32 divisors (see below), whose sum is σ = 215283240. Its totient is φ = 27015680.

The previous prime is 81047413. The next prime is 81047429. The reversal of 81047424 is 42474018.

It is a tau number, because it is divible by the number of its divisors (32).

It is a junction number, because it is equal to n+sod(n) for n = 81047391 and 81047400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81047429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105147 + ... + 105914.

Almost surely, 2^81047424 is an apocalyptic number.

It is an amenable number.

81047424 is an abundant number, since it is smaller than the sum of its proper divisors (134235816).

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

81047424 is a wasteful number, since it uses less digits than its factorization.

81047424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211078 (or 211066 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 30.

The square root of 81047424 is about 9002.6342811424. The cubic root of 81047424 is about 432.7592956595.

The spelling of 81047424 in words is "eighty-one million, forty-seven thousand, four hundred twenty-four".