1251263776249 has 4 divisors (see below), whose sum is σ = 1281782404980. Its totient is φ = 1220745147520.

The previous prime is 1251263776207. The next prime is 1251263776253. The reversal of 1251263776249 is 9426773621521.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 346944560400 + 904319215849 = 589020^2 + 950957^2 .

It is a cyclic number.

It is not a de Polignac number, because 1251263776249 - 2¹³ = 1251263768057 is a prime.

It is a super-2 number, since 2×1251263776249² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1251263776249.

It is not an unprimeable number, because it can be changed into a prime (1251263726249) 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, 15259314304 + ... + 15259314385.

It is an arithmetic number, because the mean of its divisors is an integer number (320445601245).

Almost surely, 2^{1251263776249} is an apocalyptic number.

It is an amenable number.

1251263776249 is a deficient number, since it is larger than the sum of its proper divisors (30518628731).

1251263776249 is an equidigital number, since it uses as much as digits as its factorization.

1251263776249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30518628730.

The product of its digits is 7620480, while the sum is 55.

The spelling of 1251263776249 in words is "one trillion, two hundred fifty-one billion, two hundred sixty-three million, seven hundred seventy-six thousand, two hundred forty-nine".