1206556446581 has 4 divisors (see below), whose sum is σ = 1206559060512. Its totient is φ = 1206553832652.

The previous prime is 1206556446539. The next prime is 1206556446629. The reversal of 1206556446581 is 1856446556021.

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 not a de Polignac number, because 1206556446581 - 2²⁶ = 1206489337717 is a prime.

It is a super-2 number, since 2×1206556446581² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1206556446481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 408875 + ... + 1606328.

It is an arithmetic number, because the mean of its divisors is an integer number (301639765128).

Almost surely, 2^{1206556446581} is an apocalyptic number.

It is an amenable number.

1206556446581 is a deficient number, since it is larger than the sum of its proper divisors (2613931).

1206556446581 is an equidigital number, since it uses as much as digits as its factorization.

1206556446581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2613930.

The product of its (nonzero) digits is 6912000, while the sum is 53.

The spelling of 1206556446581 in words is "one trillion, two hundred six billion, five hundred fifty-six million, four hundred forty-six thousand, five hundred eighty-one".