86978531 has 2 divisors, whose sum is σ = 86978532. Its totient is φ = 86978530.

The previous prime is 86978519. The next prime is 86978533. The reversal of 86978531 is 13587968.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 86978531 - 2¹⁰ = 86977507 is a prime.

It is a super-2 number, since 2×86978531² = 15130529709835922, which contains 22 as substring.

Together with 86978533, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (86978533) 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, 43489265 + 43489266.

It is an arithmetic number, because the mean of its divisors is an integer number (43489266).

Almost surely, 2^86978531 is an apocalyptic number.

86978531 is a deficient number, since it is larger than the sum of its proper divisors (1).

86978531 is an equidigital number, since it uses as much as digits as its factorization.

86978531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 47.

The square root of 86978531 is about 9326.2281228801. The cubic root of 86978531 is about 443.0683108331.

The spelling of 86978531 in words is "eighty-six million, nine hundred seventy-eight thousand, five hundred thirty-one".