20111210202157 has 2 divisors, whose sum is σ = 20111210202158. Its totient is φ = 20111210202156.

The previous prime is 20111210202121. The next prime is 20111210202221. The reversal of 20111210202157 is 75120201211102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18865722953961 + 1245487248196 = 4343469^2 + 1116014^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111210202157 - 2⁷ = 20111210202029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20111270202157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055605101078 + 10055605101079.

It is an arithmetic number, because the mean of its divisors is an integer number (10055605101079).

Almost surely, 2^{20111210202157} is an apocalyptic number.

It is an amenable number.

20111210202157 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111210202157 is an equidigital number, since it uses as much as digits as its factorization.

20111210202157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 560, while the sum is 25.

Adding to 20111210202157 its reverse (75120201211102), we get a palindrome (95231411413259).

The spelling of 20111210202157 in words is "twenty trillion, one hundred eleven billion, two hundred ten million, two hundred two thousand, one hundred fifty-seven".