81517480 has 32 divisors (see below), whose sum is σ = 200089440. Its totient is φ = 29642560.

The previous prime is 81517477. The next prime is 81517481. The reversal of 81517480 is 8471518.

It is not an unprimeable number, because it can be changed into a prime (81517481) 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, 92194 + ... + 93073.

It is an arithmetic number, because the mean of its divisors is an integer number (6252795).

Almost surely, 2^81517480 is an apocalyptic number.

It is an amenable number.

81517480 is an abundant number, since it is smaller than the sum of its proper divisors (118571960).

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

81517480 is a wasteful number, since it uses less digits than its factorization.

81517480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185289 (or 185285 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 34.

The square root of 81517480 is about 9028.7031183886. The cubic root of 81517480 is about 433.5943174729.

Adding to 81517480 its reverse (8471518), we get a palindrome (89988998).

The spelling of 81517480 in words is "eighty-one million, five hundred seventeen thousand, four hundred eighty".