20111111202251 has 2 divisors, whose sum is σ = 20111111202252. Its totient is φ = 20111111202250.

The previous prime is 20111111202209. The next prime is 20111111202277. The reversal of 20111111202251 is 15220211111102.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20111111202251 is a prime.

It is not a weakly prime, because it can be changed into another prime (20111111202751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055555601125 + 10055555601126.

It is an arithmetic number, because the mean of its divisors is an integer number (10055555601126).

Almost surely, 2^{20111111202251} is an apocalyptic number.

20111111202251 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111111202251 is an equidigital number, since it uses as much as digits as its factorization.

20111111202251 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 80, while the sum is 20.

Adding to 20111111202251 its reverse (15220211111102), we get a palindrome (35331322313353).

The spelling of 20111111202251 in words is "twenty trillion, one hundred eleven billion, one hundred eleven million, two hundred two thousand, two hundred fifty-one".