1281658269449 has 2 divisors, whose sum is σ = 1281658269450. Its totient is φ = 1281658269448.

The previous prime is 1281658269421. The next prime is 1281658269491. The reversal of 1281658269449 is 9449628561821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1281152334400 + 505935049 = 1131880^2 + 22493^2 .

It is a cyclic number.

It is not a de Polignac number, because 1281658269449 - 2⁸ = 1281658269193 is a prime.

It is not a weakly prime, because it can be changed into another prime (1281655269449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640829134724 + 640829134725.

It is an arithmetic number, because the mean of its divisors is an integer number (640829134725).

Almost surely, 2^{1281658269449} is an apocalyptic number.

It is an amenable number.

1281658269449 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281658269449 is an equidigital number, since it uses as much as digits as its factorization.

1281658269449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 59719680, while the sum is 65.

The spelling of 1281658269449 in words is "one trillion, two hundred eighty-one billion, six hundred fifty-eight million, two hundred sixty-nine thousand, four hundred forty-nine".