1211783157 has 12 divisors (see below), whose sum is σ = 1884996204. Its totient is φ = 745712640.

The previous prime is 1211783147. The next prime is 1211783173. The reversal of 1211783157 is 7513871121.

It can be written as a sum of positive squares in 2 ways, for example, as 130096836 + 1081686321 = 11406^2 + 32889^2 .

It is not a de Polignac number, because 1211783157 - 2⁴ = 1211783141 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211783147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5178444 + ... + 5178677.

It is an arithmetic number, because the mean of its divisors is an integer number (157083017).

Almost surely, 2^1211783157 is an apocalyptic number.

It is an amenable number.

1211783157 is a deficient number, since it is larger than the sum of its proper divisors (673213047).

1211783157 is a wasteful number, since it uses less digits than its factorization.

1211783157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10357140 (or 10357137 counting only the distinct ones).

The product of its digits is 11760, while the sum is 36.

The square root of 1211783157 is about 34810.6759055322. The cubic root of 1211783157 is about 1066.1254333097.

The spelling of 1211783157 in words is "one billion, two hundred eleven million, seven hundred eighty-three thousand, one hundred fifty-seven".