821911471867 has 16 divisors (see below), whose sum is σ = 848528305920. Its totient is φ = 795723511968.

The previous prime is 821911471859. The next prime is 821911471879. The reversal of 821911471867 is 768174119128.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 821911471867 - 2³ = 821911471859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (821911471067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17357698 + ... + 17404984.

It is an arithmetic number, because the mean of its divisors is an integer number (53033019120).

Almost surely, 2^821911471867 is an apocalyptic number.

821911471867 is a deficient number, since it is larger than the sum of its proper divisors (26616834053).

821911471867 is a wasteful number, since it uses less digits than its factorization.

821911471867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51810.

The product of its digits is 1354752, while the sum is 55.

The spelling of 821911471867 in words is "eight hundred twenty-one billion, nine hundred eleven million, four hundred seventy-one thousand, eight hundred sixty-seven".