86988721 has 2 divisors, whose sum is σ = 86988722. Its totient is φ = 86988720.

The previous prime is 86988701. The next prime is 86988743. The reversal of 86988721 is 12788968.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68807025 + 18181696 = 8295^2 + 4264^2 .

It is a cyclic number.

It is not a de Polignac number, because 86988721 - 2¹¹ = 86986673 is a prime.

It is not a weakly prime, because it can be changed into another prime (86988701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43494360 + 43494361.

It is an arithmetic number, because the mean of its divisors is an integer number (43494361).

Almost surely, 2^86988721 is an apocalyptic number.

It is an amenable number.

86988721 is a deficient number, since it is larger than the sum of its proper divisors (1).

86988721 is an equidigital number, since it uses as much as digits as its factorization.

86988721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 387072, while the sum is 49.

The square root of 86988721 is about 9326.7744156273. The cubic root of 86988721 is about 443.0856127647.

The spelling of 86988721 in words is "eighty-six million, nine hundred eighty-eight thousand, seven hundred twenty-one".