21162502909 has 2 divisors, whose sum is σ = 21162502910. Its totient is φ = 21162502908.

The previous prime is 21162502903. The next prime is 21162502937. The reversal of 21162502909 is 90920526112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12161237284 + 9001265625 = 110278^2 + 94875^2 .

It is a cyclic number.

It is not a de Polignac number, because 21162502909 - 2²¹ = 21160405757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21162502903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10581251454 + 10581251455.

It is an arithmetic number, because the mean of its divisors is an integer number (10581251455).

Almost surely, 2^21162502909 is an apocalyptic number.

It is an amenable number.

21162502909 is a deficient number, since it is larger than the sum of its proper divisors (1).

21162502909 is an equidigital number, since it uses as much as digits as its factorization.

21162502909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 37.

The spelling of 21162502909 in words is "twenty-one billion, one hundred sixty-two million, five hundred two thousand, nine hundred nine".