81313480 has 16 divisors (see below), whose sum is σ = 182955420. Its totient is φ = 32525376.

The previous prime is 81313447. The next prime is 81313481. The reversal of 81313480 is 8431318.

It can be written as a sum of positive squares in 2 ways, for example, as 79887844 + 1425636 = 8938^2 + 1194^2 .

It is a super-2 number, since 2×81313480² = 13223764059420800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81313481) 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, 1016379 + ... + 1016458.

Almost surely, 2^81313480 is an apocalyptic number.

It is an amenable number.

81313480 is an abundant number, since it is smaller than the sum of its proper divisors (101641940).

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

81313480 is a wasteful number, since it uses less digits than its factorization.

81313480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2032848 (or 2032844 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 81313480 is about 9017.3987379953. The cubic root of 81313480 is about 433.2323209655.

Adding to 81313480 its reverse (8431318), we get a palindrome (89744798).

It can be divided in two parts, 8131 and 3480, that added together give a palindrome (11611).

The spelling of 81313480 in words is "eighty-one million, three hundred thirteen thousand, four hundred eighty".