1211670561 has 8 divisors (see below), whose sum is σ = 1659224704. Its totient is φ = 785948400.

The previous prime is 1211670503. The next prime is 1211670569. The reversal of 1211670561 is 1650761121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1211670561 - 2⁶ = 1211670497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211670569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5457865 + ... + 5458086.

It is an arithmetic number, because the mean of its divisors is an integer number (207403088).

Almost surely, 2^1211670561 is an apocalyptic number.

It is an amenable number.

1211670561 is a deficient number, since it is larger than the sum of its proper divisors (447554143).

1211670561 is a wasteful number, since it uses less digits than its factorization.

1211670561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10915991.

The product of its (nonzero) digits is 2520, while the sum is 30.

The square root of 1211670561 is about 34809.0586054837. The cubic root of 1211670561 is about 1066.0924116763.

The spelling of 1211670561 in words is "one billion, two hundred eleven million, six hundred seventy thousand, five hundred sixty-one".