81820985347 has 8 divisors (see below), whose sum is σ = 82247060016. Its totient is φ = 81395019552.

The previous prime is 81820985339. The next prime is 81820985399. The reversal of 81820985347 is 74358902818.

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

It is a cyclic number.

It is not a de Polignac number, because 81820985347 - 2³ = 81820985339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81820985327) 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, 1795213 + ... + 1840225.

It is an arithmetic number, because the mean of its divisors is an integer number (10280882502).

Almost surely, 2^81820985347 is an apocalyptic number.

81820985347 is a deficient number, since it is larger than the sum of its proper divisors (426074669).

81820985347 is a wasteful number, since it uses less digits than its factorization.

81820985347 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54437.

The product of its (nonzero) digits is 3870720, while the sum is 55.

The spelling of 81820985347 in words is "eighty-one billion, eight hundred twenty million, nine hundred eighty-five thousand, three hundred forty-seven".