99974821 has 2 divisors, whose sum is σ = 99974822. Its totient is φ = 99974820.

The previous prime is 99974779. The next prime is 99974863. The reversal of 99974821 is 12847999.

It is a balanced prime because it is at equal distance from previous prime (99974779) and next prime (99974863).

It can be written as a sum of positive squares in only one way, i.e., 70392100 + 29582721 = 8390^2 + 5439^2 .

It is an emirp because it is prime and its reverse (12847999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99974821 - 2⁹ = 99974309 is a prime.

It is a zygodrome in base 4.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99974891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49987410 + 49987411.

It is an arithmetic number, because the mean of its divisors is an integer number (49987411).

Almost surely, 2^99974821 is an apocalyptic number.

It is an amenable number.

99974821 is a deficient number, since it is larger than the sum of its proper divisors (1).

99974821 is an equidigital number, since it uses as much as digits as its factorization.

99974821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 49.

The square root of 99974821 is about 9998.7409707423. The cubic root of 99974821 is about 464.1199232361.

The spelling of 99974821 in words is "ninety-nine million, nine hundred seventy-four thousand, eight hundred twenty-one".