21000002249 has 2 divisors, whose sum is σ = 21000002250. Its totient is φ = 21000002248.

The previous prime is 21000002201. The next prime is 21000002281. The reversal of 21000002249 is 94220000012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12776233024 + 8223769225 = 113032^2 + 90685^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000002249 - 2²⁴ = 20983225033 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21000002249.

It is not a weakly prime, because it can be changed into another prime (21000001249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500001124 + 10500001125.

It is an arithmetic number, because the mean of its divisors is an integer number (10500001125).

Almost surely, 2^21000002249 is an apocalyptic number.

It is an amenable number.

21000002249 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000002249 is an equidigital number, since it uses as much as digits as its factorization.

21000002249 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

The spelling of 21000002249 in words is "twenty-one billion, two thousand, two hundred forty-nine".