1211986225806 has 8 divisors (see below), whose sum is σ = 2423972451624. Its totient is φ = 403995408600.

The previous prime is 1211986225799. The next prime is 1211986225829. The reversal of 1211986225806 is 6085226891121.

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

1211986225806 is an admirable number.

It is a super-2 number, since 2×1211986225806² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100998852145 + ... + 100998852156.

It is an arithmetic number, because the mean of its divisors is an integer number (302996556453).

Almost surely, 2^{1211986225806} is an apocalyptic number.

1211986225806 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1211986225806 is a wasteful number, since it uses less digits than its factorization.

1211986225806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201997704306.

The product of its (nonzero) digits is 829440, while the sum is 51.

The spelling of 1211986225806 in words is "one trillion, two hundred eleven billion, nine hundred eighty-six million, two hundred twenty-five thousand, eight hundred six".