1251532215161 has 2 divisors, whose sum is σ = 1251532215162. Its totient is φ = 1251532215160.

The previous prime is 1251532215137. The next prime is 1251532215163. The reversal of 1251532215161 is 1615122351521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 827998083136 + 423534132025 = 909944^2 + 650795^2 .

It is a cyclic number.

It is not a de Polignac number, because 1251532215161 - 2⁶ = 1251532215097 is a prime.

Together with 1251532215163, 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 (1251532215163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 625766107580 + 625766107581.

It is an arithmetic number, because the mean of its divisors is an integer number (625766107581).

Almost surely, 2^{1251532215161} is an apocalyptic number.

It is an amenable number.

1251532215161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1251532215161 is an equidigital number, since it uses as much as digits as its factorization.

1251532215161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18000, while the sum is 35.

Adding to 1251532215161 its reverse (1615122351521), we get a palindrome (2866654566682).

The spelling of 1251532215161 in words is "one trillion, two hundred fifty-one billion, five hundred thirty-two million, two hundred fifteen thousand, one hundred sixty-one".