81855004218842 has 8 divisors (see below), whose sum is σ = 122782759782336. Its totient is φ = 40927417624732.

The previous prime is 81855004218791. The next prime is 81855004218899. The reversal of 81855004218842 is 24881240055818.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41024228 + ... + 42973215.

It is an arithmetic number, because the mean of its divisors is an integer number (15347844972792).

Almost surely, 2^{81855004218842} is an apocalyptic number.

81855004218842 is a deficient number, since it is larger than the sum of its proper divisors (40927755563494).

81855004218842 is a wasteful number, since it uses less digits than its factorization.

81855004218842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84484692.

The product of its (nonzero) digits is 6553600, while the sum is 56.

The spelling of 81855004218842 in words is "eighty-one trillion, eight hundred fifty-five billion, four million, two hundred eighteen thousand, eight hundred forty-two".