81747480 has 32 divisors (see below), whose sum is σ = 245242800. Its totient is φ = 21799296.

The previous prime is 81747469. The next prime is 81747511. The reversal of 81747480 is 8474718.

It is a congruent number.

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, 340495 + ... + 340734.

Almost surely, 2^81747480 is an apocalyptic number.

It is an amenable number.

81747480 is an abundant number, since it is smaller than the sum of its proper divisors (163495320).

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

81747480 is a wasteful number, since it uses less digits than its factorization.

81747480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 681243 (or 681239 counting only the distinct ones).

The product of its (nonzero) digits is 50176, while the sum is 39.

The square root of 81747480 is about 9041.4313026202. The cubic root of 81747480 is about 434.0017272189.

The spelling of 81747480 in words is "eighty-one million, seven hundred forty-seven thousand, four hundred eighty".