21221145149 has 2 divisors, whose sum is σ = 21221145150. Its totient is φ = 21221145148.

The previous prime is 21221145133. The next prime is 21221145191. The reversal of 21221145149 is 94154112212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18651364900 + 2569780249 = 136570^2 + 50693^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221145149 - 2⁴ = 21221145133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21221145349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610572574 + 10610572575.

It is an arithmetic number, because the mean of its divisors is an integer number (10610572575).

Almost surely, 2^21221145149 is an apocalyptic number.

It is an amenable number.

21221145149 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221145149 is an equidigital number, since it uses as much as digits as its factorization.

21221145149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5760, while the sum is 32.

The spelling of 21221145149 in words is "twenty-one billion, two hundred twenty-one million, one hundred forty-five thousand, one hundred forty-nine".