21012220969 has 2 divisors, whose sum is σ = 21012220970. Its totient is φ = 21012220968.

The previous prime is 21012220961. The next prime is 21012221047. The reversal of 21012220969 is 96902221012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15786666025 + 5225554944 = 125645^2 + 72288^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012220969 - 2³ = 21012220961 is a prime.

It is a super-2 number, since 2×21012220969² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21012220961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506110484 + 10506110485.

It is an arithmetic number, because the mean of its divisors is an integer number (10506110485).

Almost surely, 2^21012220969 is an apocalyptic number.

It is an amenable number.

21012220969 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012220969 is an equidigital number, since it uses as much as digits as its factorization.

21012220969 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 34.

The spelling of 21012220969 in words is "twenty-one billion, twelve million, two hundred twenty thousand, nine hundred sixty-nine".