1211561353 has 4 divisors (see below), whose sum is σ = 1275327760. Its totient is φ = 1147794948.

The previous prime is 1211561303. The next prime is 1211561359. The reversal of 1211561353 is 3531651121.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211561353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211561359) 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, 31883175 + ... + 31883212.

It is an arithmetic number, because the mean of its divisors is an integer number (318831940).

Almost surely, 2^1211561353 is an apocalyptic number.

It is an amenable number.

1211561353 is a deficient number, since it is larger than the sum of its proper divisors (63766407).

1211561353 is an equidigital number, since it uses as much as digits as its factorization.

1211561353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63766406.

The product of its digits is 2700, while the sum is 28.

The square root of 1211561353 is about 34807.4898980090. The cubic root of 1211561353 is about 1066.0603817055.

The spelling of 1211561353 in words is "one billion, two hundred eleven million, five hundred sixty-one thousand, three hundred fifty-three".