2181215137 has 2 divisors, whose sum is σ = 2181215138. Its totient is φ = 2181215136.

The previous prime is 2181215111. The next prime is 2181215147. The reversal of 2181215137 is 7315121812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1426119696 + 755095441 = 37764^2 + 27479^2 .

It is a cyclic number.

It is not a de Polignac number, because 2181215137 - 2¹⁵ = 2181182369 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2181215099 and 2181215108.

It is not a weakly prime, because it can be changed into another prime (2181215147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1090607568 + 1090607569.

It is an arithmetic number, because the mean of its divisors is an integer number (1090607569).

Almost surely, 2^2181215137 is an apocalyptic number.

It is an amenable number.

2181215137 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181215137 is an equidigital number, since it uses as much as digits as its factorization.

2181215137 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3360, while the sum is 31.

The square root of 2181215137 is about 46703.4809944612. The cubic root of 2181215137 is about 1296.8791286050.

Adding to 2181215137 its reverse (7315121812), we get a palindrome (9496336949).

The spelling of 2181215137 in words is "two billion, one hundred eighty-one million, two hundred fifteen thousand, one hundred thirty-seven".