81247408 has 40 divisors (see below), whose sum is σ = 179202816. Its totient is φ = 35323200.

The previous prime is 81247399. The next prime is 81247409. The reversal of 81247408 is 80474218.

It is a super-2 number, since 2×81247408² = 13202282613436928, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81247409) 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, 5988 + ... + 14083.

Almost surely, 2^81247408 is an apocalyptic number.

81247408 is a gapful number since it is divisible by the number (88) formed by its first and last digit.

It is an amenable number.

81247408 is an abundant number, since it is smaller than the sum of its proper divisors (97955408).

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

81247408 is a wasteful number, since it uses less digits than its factorization.

81247408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20113 (or 20107 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 34.

The square root of 81247408 is about 9013.7344092224. The cubic root of 81247408 is about 433.1149468948.

The spelling of 81247408 in words is "eighty-one million, two hundred forty-seven thousand, four hundred eight".