81424464 has 40 divisors (see below), whose sum is σ = 229470432. Its totient is φ = 24673920.

The previous prime is 81424463. The next prime is 81424513. The reversal of 81424464 is 46442418.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81424463) by changing a digit.

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, 76579 + ... + 77634.

Almost surely, 2^81424464 is an apocalyptic number.

It is an amenable number.

81424464 is an abundant number, since it is smaller than the sum of its proper divisors (148045968).

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

81424464 is a wasteful number, since it uses less digits than its factorization.

81424464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154235 (or 154229 counting only the distinct ones).

The product of its digits is 24576, while the sum is 33.

The square root of 81424464 is about 9023.5505207208. The cubic root of 81424464 is about 433.4293362574.

The spelling of 81424464 in words is "eighty-one million, four hundred twenty-four thousand, four hundred sixty-four".