1261375126149 has 4 divisors (see below), whose sum is σ = 1681833501536. Its totient is φ = 840916750764.

The previous prime is 1261375126129. The next prime is 1261375126163. The reversal of 1261375126149 is 9416215731621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1261375126149 - 2¹¹ = 1261375124101 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1261375126098 and 1261375126107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261375126129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 210229187689 + ... + 210229187694.

It is an arithmetic number, because the mean of its divisors is an integer number (420458375384).

Almost surely, 2^{1261375126149} is an apocalyptic number.

It is an amenable number.

1261375126149 is a deficient number, since it is larger than the sum of its proper divisors (420458375387).

1261375126149 is an equidigital number, since it uses as much as digits as its factorization.

1261375126149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420458375386.

The product of its digits is 544320, while the sum is 48.

The spelling of 1261375126149 in words is "one trillion, two hundred sixty-one billion, three hundred seventy-five million, one hundred twenty-six thousand, one hundred forty-nine".