1211707651812 has 72 divisors (see below), whose sum is σ = 3290764093344. Its totient is φ = 346008152448.

The previous prime is 1211707651801. The next prime is 1211707651853. The reversal of 1211707651812 is 2181567071121.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 474168 + ... + 1627344.

It is an arithmetic number, because the mean of its divisors is an integer number (45705056852).

Almost surely, 2^{1211707651812} is an apocalyptic number.

1211707651812 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1211707651812 is an abundant number, since it is smaller than the sum of its proper divisors (2079056441532).

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

1211707651812 is a wasteful number, since it uses less digits than its factorization.

1211707651812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1154985 (or 1154976 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 42.

The spelling of 1211707651812 in words is "one trillion, two hundred eleven billion, seven hundred seven million, six hundred fifty-one thousand, eight hundred twelve".