99790921 has 2 divisors, whose sum is σ = 99790922. Its totient is φ = 99790920.

The previous prime is 99790913. The next prime is 99790967. The reversal of 99790921 is 12909799.

It is an a-pointer prime, because the next prime (99790967) can be obtained adding 99790921 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71318025 + 28472896 = 8445^2 + 5336^2 .

It is a cyclic number.

It is not a de Polignac number, because 99790921 - 2³ = 99790913 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (99790021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49895460 + 49895461.

It is an arithmetic number, because the mean of its divisors is an integer number (49895461).

Almost surely, 2^99790921 is an apocalyptic number.

It is an amenable number.

99790921 is a deficient number, since it is larger than the sum of its proper divisors (1).

99790921 is an equidigital number, since it uses as much as digits as its factorization.

99790921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 91854, while the sum is 46.

The square root of 99790921 is about 9989.5405800267. The cubic root of 99790921 is about 463.8351714012.

The spelling of 99790921 in words is "ninety-nine million, seven hundred ninety thousand, nine hundred twenty-one".