1216643040 has 72 divisors (see below), whose sum is σ = 4151799288. Its totient is φ = 324437760.

The previous prime is 1216643027. The next prime is 1216643059. The reversal of 1216643040 is 403466121.

1216643040 is a `hidden beast` number, since 1 + 2 + 16 + 643 + 0 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a junction number, because it is equal to n+sod(n) for n = 1216642995 and 1216643013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 421006 + ... + 423885.

It is an arithmetic number, because the mean of its divisors is an integer number (57663879).

Almost surely, 2^1216643040 is an apocalyptic number.

1216643040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1216643040 is an abundant number, since it is smaller than the sum of its proper divisors (2935156248).

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

1216643040 is a wasteful number, since it uses less digits than its factorization.

1216643040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 844912 (or 844901 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 1216643040 is about 34880.4105480426. The cubic root of 1216643040 is about 1067.5487720570.

The spelling of 1216643040 in words is "one billion, two hundred sixteen million, six hundred forty-three thousand, forty".