1213162557 has 4 divisors (see below), whose sum is σ = 1617550080. Its totient is φ = 808775036.

The previous prime is 1213162541. The next prime is 1213162583. The reversal of 1213162557 is 7552613121.

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, and also an emirpimes, since its reverse is a distinct semiprime: 7552613121 = 3 ⋅2517537707.

It is a cyclic number.

It is not a de Polignac number, because 1213162557 - 2⁴ = 1213162541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213162507) 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, 202193757 + ... + 202193762.

It is an arithmetic number, because the mean of its divisors is an integer number (404387520).

Almost surely, 2^1213162557 is an apocalyptic number.

It is an amenable number.

1213162557 is a deficient number, since it is larger than the sum of its proper divisors (404387523).

1213162557 is an equidigital number, since it uses as much as digits as its factorization.

1213162557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404387522.

The product of its digits is 12600, while the sum is 33.

The square root of 1213162557 is about 34830.4831577169. The cubic root of 1213162557 is about 1066.5298114242.

Adding to 1213162557 its reverse (7552613121), we get a palindrome (8765775678).

The spelling of 1213162557 in words is "one billion, two hundred thirteen million, one hundred sixty-two thousand, five hundred fifty-seven".