21124200949 has 2 divisors, whose sum is σ = 21124200950. Its totient is φ = 21124200948.

The previous prime is 21124200883. The next prime is 21124201013. The reversal of 21124200949 is 94900242112.

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., 18039176100 + 3085024849 = 134310^2 + 55543^2 .

It is a cyclic number.

It is not a de Polignac number, because 21124200949 - 2¹⁵ = 21124168181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21124210949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562100474 + 10562100475.

It is an arithmetic number, because the mean of its divisors is an integer number (10562100475).

Almost surely, 2^21124200949 is an apocalyptic number.

It is an amenable number.

21124200949 is a deficient number, since it is larger than the sum of its proper divisors (1).

21124200949 is an equidigital number, since it uses as much as digits as its factorization.

21124200949 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 34.

The spelling of 21124200949 in words is "twenty-one billion, one hundred twenty-four million, two hundred thousand, nine hundred forty-nine".