1272250781 has 4 divisors (see below), whose sum is σ = 1273043100. Its totient is φ = 1271458464.

The previous prime is 1272250753. The next prime is 1272250813. The reversal of 1272250781 is 1870522721.

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 578402500 + 693848281 = 24050^2 + 26341^2 .

It is a cyclic number.

It is not a de Polignac number, because 1272250781 - 2²² = 1268056477 is a prime.

It is a super-2 number, since 2×1272250781² = 3237244099510219922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1272250741) 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, 393746 + ... + 396963.

It is an arithmetic number, because the mean of its divisors is an integer number (318260775).

Almost surely, 2^1272250781 is an apocalyptic number.

It is an amenable number.

1272250781 is a deficient number, since it is larger than the sum of its proper divisors (792319).

1272250781 is an equidigital number, since it uses as much as digits as its factorization.

1272250781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 792318.

The product of its (nonzero) digits is 15680, while the sum is 35.

The square root of 1272250781 is about 35668.6246020224. The cubic root of 1272250781 is about 1083.5715041051.

The spelling of 1272250781 in words is "one billion, two hundred seventy-two million, two hundred fifty thousand, seven hundred eighty-one".