20011201211957 has 2 divisors, whose sum is σ = 20011201211958. Its totient is φ = 20011201211956.

The previous prime is 20011201211951. The next prime is 20011201212029. The reversal of 20011201211957 is 75911210211002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13517872875556 + 6493328336401 = 3676666^2 + 2548201^2 .

It is a cyclic number.

It is not a de Polignac number, because 20011201211957 - 2⁴ = 20011201211941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20011201211951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10005600605978 + 10005600605979.

It is an arithmetic number, because the mean of its divisors is an integer number (10005600605979).

Almost surely, 2^{20011201211957} is an apocalyptic number.

It is an amenable number.

20011201211957 is a deficient number, since it is larger than the sum of its proper divisors (1).

20011201211957 is an equidigital number, since it uses as much as digits as its factorization.

20011201211957 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2520, while the sum is 32.

Adding to 20011201211957 its reverse (75911210211002), we get a palindrome (95922411422959).

The spelling of 20011201211957 in words is "twenty trillion, eleven billion, two hundred one million, two hundred eleven thousand, nine hundred fifty-seven".