81550452 has 24 divisors (see below), whose sum is σ = 194334336. Its totient is φ = 26604928.

The previous prime is 81550409. The next prime is 81550459. The reversal of 81550452 is 25405518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81550459) 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, 71733 + ... + 72860.

It is an arithmetic number, because the mean of its divisors is an integer number (8097264).

Almost surely, 2^81550452 is an apocalyptic number.

It is an amenable number.

81550452 is an abundant number, since it is smaller than the sum of its proper divisors (112783884).

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

81550452 is a wasteful number, since it uses less digits than its factorization.

81550452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144647 (or 144645 counting only the distinct ones).

The product of its (nonzero) digits is 8000, while the sum is 30.

The square root of 81550452 is about 9030.5288881660. The cubic root of 81550452 is about 433.6527693319.

The spelling of 81550452 in words is "eighty-one million, five hundred fifty thousand, four hundred fifty-two".