215231132509 has 2 divisors, whose sum is σ = 215231132510. Its totient is φ = 215231132508.

The previous prime is 215231132507. The next prime is 215231132527. The reversal of 215231132509 is 905231132512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132698461284 + 82532671225 = 364278^2 + 287285^2 .

It is a cyclic number.

It is not a de Polignac number, because 215231132509 - 2¹ = 215231132507 is a prime.

It is a super-2 number, since 2×215231132509² (a number of 23 digits) contains 22 as substring.

Together with 215231132507, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215231132507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107615566254 + 107615566255.

It is an arithmetic number, because the mean of its divisors is an integer number (107615566255).

Almost surely, 2^215231132509 is an apocalyptic number.

It is an amenable number.

215231132509 is a deficient number, since it is larger than the sum of its proper divisors (1).

215231132509 is an equidigital number, since it uses as much as digits as its factorization.

215231132509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16200, while the sum is 34.

The spelling of 215231132509 in words is "two hundred fifteen billion, two hundred thirty-one million, one hundred thirty-two thousand, five hundred nine".