81870357 has 16 divisors (see below), whose sum is σ = 111282560. Its totient is φ = 53524800.

The previous prime is 81870343. The next prime is 81870377. The reversal of 81870357 is 75307818.

It is not a de Polignac number, because 81870357 - 2⁶ = 81870293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81870377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 115119 + ... + 115827.

It is an arithmetic number, because the mean of its divisors is an integer number (6955160).

Almost surely, 2^81870357 is an apocalyptic number.

It is an amenable number.

81870357 is a deficient number, since it is larger than the sum of its proper divisors (29412203).

81870357 is a wasteful number, since it uses less digits than its factorization.

81870357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1404.

The product of its (nonzero) digits is 47040, while the sum is 39.

The square root of 81870357 is about 9048.2239693765. The cubic root of 81870357 is about 434.2190718697.

The spelling of 81870357 in words is "eighty-one million, eight hundred seventy thousand, three hundred fifty-seven".