891978089475 has 24 divisors (see below), whose sum is σ = 1608804119232. Its totient is φ = 432474224800.

The previous prime is 891978089461. The next prime is 891978089501. The reversal of 891978089475 is 574980879198.

It is not a de Polignac number, because 891978089475 - 2⁴ = 891978089459 is a prime.

It is a super-2 number, since 2×891978089475² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (75).

It is a junction number, because it is equal to n+sod(n) for n = 891978089397 and 891978089406.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 540591957 + ... + 540593606.

It is an arithmetic number, because the mean of its divisors is an integer number (67033504968).

Almost surely, 2^891978089475 is an apocalyptic number.

891978089475 is a deficient number, since it is larger than the sum of its proper divisors (716826029757).

891978089475 is a wasteful number, since it uses less digits than its factorization.

891978089475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1081185587 (or 1081185582 counting only the distinct ones).

The product of its (nonzero) digits is 365783040, while the sum is 75.

The spelling of 891978089475 in words is "eight hundred ninety-one billion, nine hundred seventy-eight million, eighty-nine thousand, four hundred seventy-five".