891221973362 has 54 divisors (see below), whose sum is σ = 1589665905837. Its totient is φ = 373641388848.

The previous prime is 891221973353. The next prime is 891221973377. The reversal of 891221973362 is 263379122198.

It can be written as a sum of positive squares in 2 ways, for example, as 524362808641 + 366859164721 = 724129^2 + 605689^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=667541.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 439240964 + ... + 439242992.

Almost surely, 2^891221973362 is an apocalyptic number.

891221973362 is a deficient number, since it is larger than the sum of its proper divisors (698443932475).

891221973362 is an frugal number, since it uses more digits than its factorization.

891221973362 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4168 (or 2085 counting only the distinct ones).

The product of its digits is 1959552, while the sum is 53.

The spelling of 891221973362 in words is "eight hundred ninety-one billion, two hundred twenty-one million, nine hundred seventy-three thousand, three hundred sixty-two".