21201002209949 has 2 divisors, whose sum is σ = 21201002209950. Its totient is φ = 21201002209948.

The previous prime is 21201002209927. The next prime is 21201002210053. The reversal of 21201002209949 is 94990220010212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13041307125625 + 8159695084324 = 3611275^2 + 2856518^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21201002209949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21201002209649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600501104974 + 10600501104975.

It is an arithmetic number, because the mean of its divisors is an integer number (10600501104975).

Almost surely, 2^{21201002209949} is an apocalyptic number.

It is an amenable number.

21201002209949 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201002209949 is an equidigital number, since it uses as much as digits as its factorization.

21201002209949 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 41.

The spelling of 21201002209949 in words is "twenty-one trillion, two hundred one billion, two million, two hundred nine thousand, nine hundred forty-nine".