99478021 has 2 divisors, whose sum is σ = 99478022. Its totient is φ = 99478020.

The previous prime is 99478009. The next prime is 99478037. The reversal of 99478021 is 12087499.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 92428996 + 7049025 = 9614^2 + 2655^2 .

It is a cyclic number.

It is not a de Polignac number, because 99478021 - 2⁷ = 99477893 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 (99478051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49739010 + 49739011.

It is an arithmetic number, because the mean of its divisors is an integer number (49739011).

Almost surely, 2^99478021 is an apocalyptic number.

It is an amenable number.

99478021 is a deficient number, since it is larger than the sum of its proper divisors (1).

99478021 is an equidigital number, since it uses as much as digits as its factorization.

99478021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 99478021 is about 9973.8669030622. The cubic root of 99478021 is about 463.3498701319.

The spelling of 99478021 in words is "ninety-nine million, four hundred seventy-eight thousand, twenty-one".