2151281171321 has 2 divisors, whose sum is σ = 2151281171322. Its totient is φ = 2151281171320.

The previous prime is 2151281171269. The next prime is 2151281171323. The reversal of 2151281171321 is 1231711821512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1155756153721 + 995525017600 = 1075061^2 + 997760^2 .

It is a cyclic number.

It is not a de Polignac number, because 2151281171321 - 2³⁸ = 1876403264377 is a prime.

Together with 2151281171323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2151281171323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1075640585660 + 1075640585661.

It is an arithmetic number, because the mean of its divisors is an integer number (1075640585661).

Almost surely, 2^{2151281171321} is an apocalyptic number.

It is an amenable number.

2151281171321 is a deficient number, since it is larger than the sum of its proper divisors (1).

2151281171321 is an equidigital number, since it uses as much as digits as its factorization.

2151281171321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 35.

Adding to 2151281171321 its reverse (1231711821512), we get a palindrome (3382992992833).

The spelling of 2151281171321 in words is "two trillion, one hundred fifty-one billion, two hundred eighty-one million, one hundred seventy-one thousand, three hundred twenty-one".