21021012109969 has 2 divisors, whose sum is σ = 21021012109970. Its totient is φ = 21021012109968.

The previous prime is 21021012109883. The next prime is 21021012110017. The reversal of 21021012109969 is 96990121012012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20889470250000 + 131541859969 = 4570500^2 + 362687^2 .

It is a cyclic number.

It is not a de Polignac number, because 21021012109969 - 2¹³ = 21021012101777 is a prime.

It is a super-2 number, since 2×21021012109969² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21021012100969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510506054984 + 10510506054985.

It is an arithmetic number, because the mean of its divisors is an integer number (10510506054985).

Almost surely, 2^{21021012109969} is an apocalyptic number.

It is an amenable number.

21021012109969 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021012109969 is an equidigital number, since it uses as much as digits as its factorization.

21021012109969 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 43.

The spelling of 21021012109969 in words is "twenty-one trillion, twenty-one billion, twelve million, one hundred nine thousand, nine hundred sixty-nine".