99786221 has 2 divisors, whose sum is σ = 99786222. Its totient is φ = 99786220.

The previous prime is 99786139. The next prime is 99786257. The reversal of 99786221 is 12268799.

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., 67010596 + 32775625 = 8186^2 + 5725^2 .

It is a cyclic number.

It is not a de Polignac number, because 99786221 - 2¹⁸ = 99524077 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 (99486221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49893110 + 49893111.

It is an arithmetic number, because the mean of its divisors is an integer number (49893111).

Almost surely, 2^99786221 is an apocalyptic number.

It is an amenable number.

99786221 is a deficient number, since it is larger than the sum of its proper divisors (1).

99786221 is an equidigital number, since it uses as much as digits as its factorization.

99786221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 44.

The square root of 99786221 is about 9989.3053312030. The cubic root of 99786221 is about 463.8278893108.

The spelling of 99786221 in words is "ninety-nine million, seven hundred eighty-six thousand, two hundred twenty-one".