1211211097 has 4 divisors (see below), whose sum is σ = 1213970560. Its totient is φ = 1208451636.

The previous prime is 1211211077. The next prime is 1211211203. The reversal of 1211211097 is 7901121121.

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: 7901121121 = 53 ⋅149077757.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211211097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211211077) 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, 1379073 + ... + 1379950.

It is an arithmetic number, because the mean of its divisors is an integer number (303492640).

Almost surely, 2^1211211097 is an apocalyptic number.

It is an amenable number.

1211211097 is a deficient number, since it is larger than the sum of its proper divisors (2759463).

1211211097 is an equidigital number, since it uses as much as digits as its factorization.

1211211097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2759462.

The product of its (nonzero) digits is 252, while the sum is 25.

The square root of 1211211097 is about 34802.4582034086. The cubic root of 1211211097 is about 1065.9576409922.

The spelling of 1211211097 in words is "one billion, two hundred eleven million, two hundred eleven thousand, ninety-seven".