99039821 has 2 divisors, whose sum is σ = 99039822. Its totient is φ = 99039820.

The previous prime is 99039797. The next prime is 99039827. The reversal of 99039821 is 12893099.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 93818596 + 5221225 = 9686^2 + 2285^2 .

It is an emirp because it is prime and its reverse (12893099) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99039821 - 2¹⁴ = 99023437 is a prime.

It is a super-2 number, since 2×99039821² = 19617772287424082, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99039827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49519910 + 49519911.

It is an arithmetic number, because the mean of its divisors is an integer number (49519911).

Almost surely, 2^99039821 is an apocalyptic number.

It is an amenable number.

99039821 is a deficient number, since it is larger than the sum of its proper divisors (1).

99039821 is an equidigital number, since it uses as much as digits as its factorization.

99039821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 41.

The square root of 99039821 is about 9951.8752504239. The cubic root of 99039821 is about 462.6685176998.

The spelling of 99039821 in words is "ninety-nine million, thirty-nine thousand, eight hundred twenty-one".