1206521861 has 8 divisors (see below), whose sum is σ = 1226552448. Its totient is φ = 1186650000.

The previous prime is 1206521851. The next prime is 1206521903. The reversal of 1206521861 is 1681256021.

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

It is a cyclic number.

It is not a de Polignac number, because 1206521861 - 2¹⁴ = 1206505477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1206521851) 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, 24305 + ... + 54806.

It is an arithmetic number, because the mean of its divisors is an integer number (153319056).

Almost surely, 2^1206521861 is an apocalyptic number.

It is an amenable number.

1206521861 is a deficient number, since it is larger than the sum of its proper divisors (20030587).

1206521861 is a wasteful number, since it uses less digits than its factorization.

1206521861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79363.

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 1206521861 is about 34735.0235497257. The cubic root of 1206521861 is about 1064.5802341111.

Adding to 1206521861 its reverse (1681256021), we get a palindrome (2887777882).

The spelling of 1206521861 in words is "one billion, two hundred six million, five hundred twenty-one thousand, eight hundred sixty-one".