2100232111981 has 2 divisors, whose sum is σ = 2100232111982. Its totient is φ = 2100232111980.

The previous prime is 2100232111951. The next prime is 2100232112023. The reversal of 2100232111981 is 1891112320012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2090655728100 + 9576383881 = 1445910^2 + 97859^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100232111981 - 2²¹ = 2100230014829 is a prime.

It is a super-2 number, since 2×2100232111981² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2100232111951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050116055990 + 1050116055991.

It is an arithmetic number, because the mean of its divisors is an integer number (1050116055991).

Almost surely, 2^{2100232111981} is an apocalyptic number.

It is an amenable number.

2100232111981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2100232111981 is an equidigital number, since it uses as much as digits as its factorization.

2100232111981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 31.

Adding to 2100232111981 its reverse (1891112320012), we get a palindrome (3991344431993).

The spelling of 2100232111981 in words is "two trillion, one hundred billion, two hundred thirty-two million, one hundred eleven thousand, nine hundred eighty-one".