20121101857 has 2 divisors, whose sum is σ = 20121101858. Its totient is φ = 20121101856.

The previous prime is 20121101801. The next prime is 20121101873. The reversal of 20121101857 is 75810112102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16889861521 + 3231240336 = 129961^2 + 56844^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121101857 - 2¹¹ = 20121099809 is a prime.

It is not a weakly prime, because it can be changed into another prime (20121101057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060550928 + 10060550929.

It is an arithmetic number, because the mean of its divisors is an integer number (10060550929).

Almost surely, 2^20121101857 is an apocalyptic number.

It is an amenable number.

20121101857 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121101857 is an equidigital number, since it uses as much as digits as its factorization.

20121101857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1120, while the sum is 28.

Adding to 20121101857 its reverse (75810112102), we get a palindrome (95931213959).

The spelling of 20121101857 in words is "twenty billion, one hundred twenty-one million, one hundred one thousand, eight hundred fifty-seven".