81470139 has 8 divisors (see below), whose sum is σ = 112131072. Its totient is φ = 52561320.

The previous prime is 81470131. The next prime is 81470141. The reversal of 81470139 is 93107418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81470139 - 2³ = 81470131 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (81470131) 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, 437919 + ... + 438104.

It is an arithmetic number, because the mean of its divisors is an integer number (14016384).

Almost surely, 2^81470139 is an apocalyptic number.

81470139 is a deficient number, since it is larger than the sum of its proper divisors (30660933).

81470139 is a wasteful number, since it uses less digits than its factorization.

81470139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 876057.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 81470139 is about 9026.0810432878. The cubic root of 81470139 is about 433.5103650761.

The spelling of 81470139 in words is "eighty-one million, four hundred seventy thousand, one hundred thirty-nine".