981897869 has 2 divisors, whose sum is σ = 981897870. Its totient is φ = 981897868.

The previous prime is 981897859. The next prime is 981897893. The reversal of 981897869 is 968798189.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 971257225 + 10640644 = 31165^2 + 3262^2 .

It is an emirp because it is prime and its reverse (968798189) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 981897869 - 2²⁸ = 713462413 is a prime.

It is a super-2 number, since 2×981897869² = 1928246850293482322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (981897809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 490948934 + 490948935.

It is an arithmetic number, because the mean of its divisors is an integer number (490948935).

Almost surely, 2^981897869 is an apocalyptic number.

It is an amenable number.

981897869 is a deficient number, since it is larger than the sum of its proper divisors (1).

981897869 is an equidigital number, since it uses as much as digits as its factorization.

981897869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15676416, while the sum is 65.

The square root of 981897869 is about 31335.2496240257. The cubic root of 981897869 is about 993.9291760093.

The spelling of 981897869 in words is "nine hundred eighty-one million, eight hundred ninety-seven thousand, eight hundred sixty-nine".