86897981 has 2 divisors, whose sum is σ = 86897982. Its totient is φ = 86897980.

The previous prime is 86897939. The next prime is 86898011. The reversal of 86897981 is 18979868.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 86025625 + 872356 = 9275^2 + 934^2 .

It is a cyclic number.

It is not a de Polignac number, because 86897981 - 2⁶ = 86897917 is a prime.

It is a super-2 number, since 2×86897981² = 15102518203752722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (86890981) by changing a digit.

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 as a sum of consecutive naturals, namely, 43448990 + 43448991.

It is an arithmetic number, because the mean of its divisors is an integer number (43448991).

Almost surely, 2^86897981 is an apocalyptic number.

It is an amenable number.

86897981 is a deficient number, since it is larger than the sum of its proper divisors (1).

86897981 is an equidigital number, since it uses as much as digits as its factorization.

86897981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1741824, while the sum is 56.

The square root of 86897981 is about 9321.9086564930. The cubic root of 86897981 is about 442.9314947904.

It can be divided in two parts, 86897 and 981, that added together give a palindrome (87878).

The spelling of 86897981 in words is "eighty-six million, eight hundred ninety-seven thousand, nine hundred eighty-one".