215643533137 has 2 divisors, whose sum is σ = 215643533138. Its totient is φ = 215643533136.

The previous prime is 215643533123. The next prime is 215643533191. The reversal of 215643533137 is 731335346512.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 204592477761 + 11051055376 = 452319^2 + 105124^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215643533137 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 215643533093 and 215643533102.

It is not a weakly prime, because it can be changed into another prime (215643533117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107821766568 + 107821766569.

It is an arithmetic number, because the mean of its divisors is an integer number (107821766569).

Almost surely, 2^215643533137 is an apocalyptic number.

It is an amenable number.

215643533137 is a deficient number, since it is larger than the sum of its proper divisors (1).

215643533137 is an equidigital number, since it uses as much as digits as its factorization.

215643533137 is an evil number, because the sum of its binary digits is even.

The product of its digits is 680400, while the sum is 43.

Adding to 215643533137 its reverse (731335346512), we get a palindrome (946978879649).

The spelling of 215643533137 in words is "two hundred fifteen billion, six hundred forty-three million, five hundred thirty-three thousand, one hundred thirty-seven".