2155432505209 has 2 divisors, whose sum is σ = 2155432505210. Its totient is φ = 2155432505208.

The previous prime is 2155432505183. The next prime is 2155432505251. The reversal of 2155432505209 is 9025052345512.

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., 2059454606400 + 95977898809 = 1435080^2 + 309803^2 .

It is a cyclic number.

It is not a de Polignac number, because 2155432505209 - 2⁷ = 2155432505081 is a prime.

It is not a weakly prime, because it can be changed into another prime (2155432505299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1077716252604 + 1077716252605.

It is an arithmetic number, because the mean of its divisors is an integer number (1077716252605).

Almost surely, 2^{2155432505209} is an apocalyptic number.

It is an amenable number.

2155432505209 is a deficient number, since it is larger than the sum of its proper divisors (1).

2155432505209 is an equidigital number, since it uses as much as digits as its factorization.

2155432505209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 540000, while the sum is 43.

The spelling of 2155432505209 in words is "two trillion, one hundred fifty-five billion, four hundred thirty-two million, five hundred five thousand, two hundred nine".