1213531372816 has 45 divisors (see below), whose sum is σ = 2735158724631. Its totient is φ = 520071654816.

The previous prime is 1213531372813. The next prime is 1213531372841. The reversal of 1213531372816 is 6182731353121.

The square root of 1213531372816 is 1101604.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1213531372813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 30825241 + ... + 30864583.

Almost surely, 2^{1213531372816} is an apocalyptic number.

1213531372816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

1213531372816 is the 1101604-th square number.

It is an amenable number.

1213531372816 is an abundant number, since it is smaller than the sum of its proper divisors (1521627351815).

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

1213531372816 is an frugal number, since it uses more digits than its factorization.

1213531372816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78708 (or 39352 counting only the distinct ones).

The product of its digits is 181440, while the sum is 43.

The spelling of 1213531372816 in words is "one trillion, two hundred thirteen billion, five hundred thirty-one million, three hundred seventy-two thousand, eight hundred sixteen".