891997969 has 2 divisors, whose sum is σ = 891997970. Its totient is φ = 891997968.

The previous prime is 891997957. The next prime is 891998011. The reversal of 891997969 is 969799198.

891997969 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 889232400 + 2765569 = 29820^2 + 1663^2 .

It is a cyclic number.

It is not a de Polignac number, because 891997969 - 2¹¹ = 891995921 is a prime.

It is a super-2 number, since 2×891997969² = 1591320753400249922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (891997919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 445998984 + 445998985.

It is an arithmetic number, because the mean of its divisors is an integer number (445998985).

Almost surely, 2^891997969 is an apocalyptic number.

It is an amenable number.

891997969 is a deficient number, since it is larger than the sum of its proper divisors (1).

891997969 is an equidigital number, since it uses as much as digits as its factorization.

891997969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19840464, while the sum is 67.

The square root of 891997969 is about 29866.3350446619. The cubic root of 891997969 is about 962.6194264359.

The spelling of 891997969 in words is "eight hundred ninety-one million, nine hundred ninety-seven thousand, nine hundred sixty-nine".