1216404648 has 64 divisors (see below), whose sum is σ = 3381840000. Its totient is φ = 405115776.

The previous prime is 1216404647. The next prime is 1216404649. The reversal of 1216404648 is 8464046121.

It is a happy number.

1216404648 is a `hidden beast` number, since 1 + 2 + 1 + 6 + 4 + 0 + 4 + 648 = 666.

It is an interprime number because it is at equal distance from previous prime (1216404647) and next prime (1216404649).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (1216404641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 397428 + ... + 400476.

It is an arithmetic number, because the mean of its divisors is an integer number (52841250).

Almost surely, 2^1216404648 is an apocalyptic number.

1216404648 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1216404648 is an abundant number, since it is smaller than the sum of its proper divisors (2165435352).

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

1216404648 is a wasteful number, since it uses less digits than its factorization.

1216404648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4911 (or 4901 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The square root of 1216404648 is about 34876.9931043374. The cubic root of 1216404648 is about 1067.4790414670.

The spelling of 1216404648 in words is "one billion, two hundred sixteen million, four hundred four thousand, six hundred forty-eight".