81562436 has 6 divisors (see below), whose sum is σ = 142734270. Its totient is φ = 40781216.

The previous prime is 81562433. The next prime is 81562463. The reversal of 81562436 is 63426518.

It can be written as a sum of positive squares in only one way, i.e., 75342400 + 6220036 = 8680^2 + 2494^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81562396 and 81562405.

It is not an unprimeable number, because it can be changed into a prime (81562433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10195301 + ... + 10195308.

It is an arithmetic number, because the mean of its divisors is an integer number (23789045).

Almost surely, 2^81562436 is an apocalyptic number.

It is an amenable number.

81562436 is a deficient number, since it is larger than the sum of its proper divisors (61171834).

81562436 is a wasteful number, since it uses less digits than its factorization.

81562436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20390613 (or 20390611 counting only the distinct ones).

The product of its digits is 34560, while the sum is 35.

The square root of 81562436 is about 9031.1923908197. The cubic root of 81562436 is about 433.6740103352.

The spelling of 81562436 in words is "eighty-one million, five hundred sixty-two thousand, four hundred thirty-six".