81513480 has 32 divisors (see below), whose sum is σ = 244540800. Its totient is φ = 21736896.

The previous prime is 81513469. The next prime is 81513491. The reversal of 81513480 is 8431518.

It is an interprime number because it is at equal distance from previous prime (81513469) and next prime (81513491).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 339520 + ... + 339759.

It is an arithmetic number, because the mean of its divisors is an integer number (7641900).

Almost surely, 2^81513480 is an apocalyptic number.

It is an amenable number.

81513480 is an abundant number, since it is smaller than the sum of its proper divisors (163027320).

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

81513480 is a wasteful number, since it uses less digits than its factorization.

81513480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679293 (or 679289 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 30.

The square root of 81513480 is about 9028.4815999148. The cubic root of 81513480 is about 433.5872253105.

Adding to 81513480 its reverse (8431518), we get a palindrome (89944998).

The spelling of 81513480 in words is "eighty-one million, five hundred thirteen thousand, four hundred eighty".