86720989 has 2 divisors, whose sum is σ = 86720990. Its totient is φ = 86720988.

The previous prime is 86720987. The next prime is 86720993. The reversal of 86720989 is 98902768.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49815364 + 36905625 = 7058^2 + 6075^2 .

It is a cyclic number.

It is not a de Polignac number, because 86720989 - 2¹ = 86720987 is a prime.

Together with 86720987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (86720983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43360494 + 43360495.

It is an arithmetic number, because the mean of its divisors is an integer number (43360495).

Almost surely, 2^86720989 is an apocalyptic number.

It is an amenable number.

86720989 is a deficient number, since it is larger than the sum of its proper divisors (1).

86720989 is an equidigital number, since it uses as much as digits as its factorization.

86720989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 435456, while the sum is 49.

The square root of 86720989 is about 9312.4104827912. The cubic root of 86720989 is about 442.6305725089.

The spelling of 86720989 in words is "eighty-six million, seven hundred twenty thousand, nine hundred eighty-nine".