1213561976 has 64 divisors (see below), whose sum is σ = 2528064000. Its totient is φ = 541532160.

The previous prime is 1213561969. The next prime is 1213561981. The reversal of 1213561976 is 6791653121.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1577720 + ... + 1578488.

It is an arithmetic number, because the mean of its divisors is an integer number (39501000).

Almost surely, 2^1213561976 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1213561976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1264032000).

1213561976 is an abundant number, since it is smaller than the sum of its proper divisors (1314502024).

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

1213561976 is a wasteful number, since it uses less digits than its factorization.

1213561976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1092 (or 1088 counting only the distinct ones).

The product of its digits is 68040, while the sum is 41.

The square root of 1213561976 is about 34836.2164420880. The cubic root of 1213561976 is about 1066.6468458991.

The spelling of 1213561976 in words is "one billion, two hundred thirteen million, five hundred sixty-one thousand, nine hundred seventy-six".