1216804780 has 48 divisors (see below), whose sum is σ = 2592092160. Its totient is φ = 479763648.

The previous prime is 1216804751. The next prime is 1216804861. The reversal of 1216804780 is 874086121.

It is a super-2 number, since 2×1216804780² = 2961227745261696800, which contains 22 as substring.

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, 412551 + ... + 415489.

It is an arithmetic number, because the mean of its divisors is an integer number (54001920).

Almost surely, 2^1216804780 is an apocalyptic number.

1216804780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1216804780 is an abundant number, since it is smaller than the sum of its proper divisors (1375287380).

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

1216804780 is a wasteful number, since it uses less digits than its factorization.

1216804780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3238 (or 3236 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 37.

The square root of 1216804780 is about 34882.7289643457. The cubic root of 1216804780 is about 1067.5960764516.

The spelling of 1216804780 in words is "one billion, two hundred sixteen million, eight hundred four thousand, seven hundred eighty".