87827981 has 2 divisors, whose sum is σ = 87827982. Its totient is φ = 87827980.

The previous prime is 87827969. The next prime is 87827989. The reversal of 87827981 is 18972878.

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., 86955625 + 872356 = 9325^2 + 934^2 .

It is a cyclic number.

It is not a de Polignac number, because 87827981 - 2⁶ = 87827917 is a prime.

It is a super-2 number, since 2×87827981² = 15427508493072722, 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 (87827989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43913990 + 43913991.

It is an arithmetic number, because the mean of its divisors is an integer number (43913991).

Almost surely, 2^87827981 is an apocalyptic number.

It is an amenable number.

87827981 is a deficient number, since it is larger than the sum of its proper divisors (1).

87827981 is an equidigital number, since it uses as much as digits as its factorization.

87827981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 451584, while the sum is 50.

The square root of 87827981 is about 9371.6583911280. The cubic root of 87827981 is about 444.5060057064.

The spelling of 87827981 in words is "eighty-seven million, eight hundred twenty-seven thousand, nine hundred eighty-one".