81552040 has 16 divisors (see below), whose sum is σ = 183492180. Its totient is φ = 32620800.

The previous prime is 81552019. The next prime is 81552049. The reversal of 81552040 is 4025518.

It can be written as a sum of positive squares in 2 ways, for example, as 76632516 + 4919524 = 8754^2 + 2218^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81551996 and 81552014.

It is not an unprimeable number, because it can be changed into a prime (81552049) 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, 1019361 + ... + 1019440.

Almost surely, 2^81552040 is an apocalyptic number.

It is an amenable number.

81552040 is an abundant number, since it is smaller than the sum of its proper divisors (101940140).

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

81552040 is a wasteful number, since it uses less digits than its factorization.

81552040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2038812 (or 2038808 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 25.

The square root of 81552040 is about 9030.6168117134. The cubic root of 81552040 is about 433.6555840971.

Adding to 81552040 its reverse (4025518), we get a palindrome (85577558).

The spelling of 81552040 in words is "eighty-one million, five hundred fifty-two thousand, forty".