21012112112137 has 2 divisors, whose sum is σ = 21012112112138. Its totient is φ = 21012112112136.

The previous prime is 21012112112099. The next prime is 21012112112143. The reversal of 21012112112137 is 73121121121012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13221448649161 + 7790663462976 = 3636131^2 + 2791176^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012112112137 - 2⁷ = 21012112112009 is a prime.

It is not a weakly prime, because it can be changed into another prime (21012112112197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506056056068 + 10506056056069.

It is an arithmetic number, because the mean of its divisors is an integer number (10506056056069).

Almost surely, 2^{21012112112137} is an apocalyptic number.

It is an amenable number.

21012112112137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012112112137 is an equidigital number, since it uses as much as digits as its factorization.

21012112112137 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 336, while the sum is 25.

Adding to 21012112112137 its reverse (73121121121012), we get a palindrome (94133233233149).

The spelling of 21012112112137 in words is "twenty-one trillion, twelve billion, one hundred twelve million, one hundred twelve thousand, one hundred thirty-seven".