1261426386971 has 2 divisors, whose sum is σ = 1261426386972. Its totient is φ = 1261426386970.

The previous prime is 1261426386967. The next prime is 1261426387003. The reversal of 1261426386971 is 1796836241621.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1261426386971 - 2² = 1261426386967 is a prime.

It is a super-2 number, since 2×1261426386971² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1261425386971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630713193485 + 630713193486.

It is an arithmetic number, because the mean of its divisors is an integer number (630713193486).

Almost surely, 2^{1261426386971} is an apocalyptic number.

1261426386971 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261426386971 is an equidigital number, since it uses as much as digits as its factorization.

1261426386971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5225472, while the sum is 56.

The spelling of 1261426386971 in words is "one trillion, two hundred sixty-one billion, four hundred twenty-six million, three hundred eighty-six thousand, nine hundred seventy-one".