1211631912 has 32 divisors (see below), whose sum is σ = 3365644800. Its totient is φ = 403877232.

The previous prime is 1211631907. The next prime is 1211631913. The reversal of 1211631912 is 2191361121.

It is a happy number.

1211631912 is a `hidden beast` number, since 1 + 2 + 11 + 631 + 9 + 12 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (1211631913) 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, 2804488 + ... + 2804919.

It is an arithmetic number, because the mean of its divisors is an integer number (105176400).

Almost surely, 2^1211631912 is an apocalyptic number.

1211631912 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1211631912 is an abundant number, since it is smaller than the sum of its proper divisors (2154012888).

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

1211631912 is a wasteful number, since it uses less digits than its factorization.

1211631912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5609422 (or 5609412 counting only the distinct ones).

The product of its digits is 648, while the sum is 27.

The square root of 1211631912 is about 34808.5034438426. The cubic root of 1211631912 is about 1066.0810764050.

The spelling of 1211631912 in words is "one billion, two hundred eleven million, six hundred thirty-one thousand, nine hundred twelve".