99986521 has 2 divisors, whose sum is σ = 99986522. Its totient is φ = 99986520.

The previous prime is 99986507. The next prime is 99986527. The reversal of 99986521 is 12568999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80802121 + 19184400 = 8989^2 + 4380^2 .

It is a cyclic number.

It is not a de Polignac number, because 99986521 - 2⁵ = 99986489 is a prime.

It is a nialpdrome in base 10.

It is not a weakly prime, because it can be changed into another prime (99986527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49993260 + 49993261.

It is an arithmetic number, because the mean of its divisors is an integer number (49993261).

Almost surely, 2^99986521 is an apocalyptic number.

It is an amenable number.

99986521 is a deficient number, since it is larger than the sum of its proper divisors (1).

99986521 is an equidigital number, since it uses as much as digits as its factorization.

99986521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 349920, while the sum is 49.

The square root of 99986521 is about 9999.3260272880. The cubic root of 99986521 is about 464.1380277656.

The spelling of 99986521 in words is "ninety-nine million, nine hundred eighty-six thousand, five hundred twenty-one".