215155400309 has 2 divisors, whose sum is σ = 215155400310. Its totient is φ = 215155400308.

The previous prime is 215155400287. The next prime is 215155400347. The reversal of 215155400309 is 903004551512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 201161220100 + 13994180209 = 448510^2 + 118297^2 .

It is a cyclic number.

It is not a de Polignac number, because 215155400309 - 2²⁴ = 215138623093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215155000309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107577700154 + 107577700155.

It is an arithmetic number, because the mean of its divisors is an integer number (107577700155).

Almost surely, 2^215155400309 is an apocalyptic number.

It is an amenable number.

215155400309 is a deficient number, since it is larger than the sum of its proper divisors (1).

215155400309 is an equidigital number, since it uses as much as digits as its factorization.

215155400309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27000, while the sum is 35.

The spelling of 215155400309 in words is "two hundred fifteen billion, one hundred fifty-five million, four hundred thousand, three hundred nine".