20121111092009 has 2 divisors, whose sum is σ = 20121111092010. Its totient is φ = 20121111092008.

The previous prime is 20121111091987. The next prime is 20121111092029. The reversal of 20121111092009 is 90029011112102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19741004317225 + 380106774784 = 4443085^2 + 616528^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121111092009 - 2¹⁶ = 20121111026473 is a prime.

It is a super-2 number, since 2×20121111092009² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20121111092029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060555546004 + 10060555546005.

It is an arithmetic number, because the mean of its divisors is an integer number (10060555546005).

Almost surely, 2^{20121111092009} is an apocalyptic number.

It is an amenable number.

20121111092009 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121111092009 is an equidigital number, since it uses as much as digits as its factorization.

20121111092009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 29.

The spelling of 20121111092009 in words is "twenty trillion, one hundred twenty-one billion, one hundred eleven million, ninety-two thousand, nine".