1221614640 has 240 divisors, whose sum is σ = 4345436160. Its totient is φ = 306915840.

The previous prime is 1221614629. The next prime is 1221614657. The reversal of 1221614640 is 464161221.

1221614640 is a `hidden beast` number, since 1 + 2 + 2 + 1 + 6 + 14 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 1175241 + ... + 1176279.

It is an arithmetic number, because the mean of its divisors is an integer number (18105984).

Almost surely, 2^1221614640 is an apocalyptic number.

1221614640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221614640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2172718080).

1221614640 is an abundant number, since it is smaller than the sum of its proper divisors (3123821520).

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

1221614640 is a wasteful number, since it uses less digits than its factorization.

1221614640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1152 (or 1143 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 1221614640 is about 34951.6042550267. The cubic root of 1221614640 is about 1069.0009132844. Note that the first 3 decimals are identical.

Adding to 1221614640 its reverse (464161221), we get a palindrome (1685775861).

The spelling of 1221614640 in words is "one billion, two hundred twenty-one million, six hundred fourteen thousand, six hundred forty".