1213212780 has 72 divisors (see below), whose sum is σ = 3963169392. Its totient is φ = 298636416.

The previous prime is 1213212703. The next prime is 1213212797. The reversal of 1213212780 is 872123121.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 256894 + ... + 261573.

Almost surely, 2^1213212780 is an apocalyptic number.

1213212780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1213212780 is an abundant number, since it is smaller than the sum of its proper divisors (2749956612).

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

1213212780 is a wasteful number, since it uses less digits than its factorization.

1213212780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 518495 (or 518490 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 1213212780 is about 34831.2041135531. The cubic root of 1213212780 is about 1066.5445287670.

The spelling of 1213212780 in words is "one billion, two hundred thirteen million, two hundred twelve thousand, seven hundred eighty".