21001312223137 has 2 divisors, whose sum is σ = 21001312223138. Its totient is φ = 21001312223136.

The previous prime is 21001312223107. The next prime is 21001312223141. The reversal of 21001312223137 is 73132221310012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11086975343521 + 9914336879616 = 3329711^2 + 3148704^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001312223137 - 2⁷ = 21001312223009 is a prime.

It is a super-2 number, since 2×21001312223137² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21001312223107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500656111568 + 10500656111569.

It is an arithmetic number, because the mean of its divisors is an integer number (10500656111569).

Almost surely, 2^{21001312223137} is an apocalyptic number.

It is an amenable number.

21001312223137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001312223137 is an equidigital number, since it uses as much as digits as its factorization.

21001312223137 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 28.

Adding to 21001312223137 its reverse (73132221310012), we get a palindrome (94133533533149).

It can be divided in two parts, 21001312 and 223137, that added together give a square (21224449 = 4607²).

The spelling of 21001312223137 in words is "twenty-one trillion, one billion, three hundred twelve million, two hundred twenty-three thousand, one hundred thirty-seven".