99500021 has 2 divisors, whose sum is σ = 99500022. Its totient is φ = 99500020.

The previous prime is 99499991. The next prime is 99500033. The reversal of 99500021 is 12000599.

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., 84180625 + 15319396 = 9175^2 + 3914^2 .

It is a cyclic number.

It is not a de Polignac number, because 99500021 - 2¹⁸ = 99237877 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99500041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49750010 + 49750011.

It is an arithmetic number, because the mean of its divisors is an integer number (49750011).

Almost surely, 2^99500021 is an apocalyptic number.

It is an amenable number.

99500021 is a deficient number, since it is larger than the sum of its proper divisors (1).

99500021 is an equidigital number, since it uses as much as digits as its factorization.

99500021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 810, while the sum is 26.

The square root of 99500021 is about 9974.9697242648. The cubic root of 99500021 is about 463.3840248985.

The spelling of 99500021 in words is "ninety-nine million, five hundred thousand, twenty-one".