2143556640 has 72 divisors (see below), whose sum is σ = 7314891948. Its totient is φ = 571614720.

The previous prime is 2143556627. The next prime is 2143556641. The reversal of 2143556640 is 466553412.

2143556640 is a `hidden beast` number, since 2 + 1 + 4 + 3 + 5 + 5 + 6 + 640 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1852785936 + 290770704 = 43044^2 + 17052^2 .

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

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

It is a junction number, because it is equal to n+sod(n) for n = 2143556595 and 2143556604.

It is not an unprimeable number, because it can be changed into a prime (2143556641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 742851 + ... + 745730.

Almost surely, 2^2143556640 is an apocalyptic number.

2143556640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2143556640 is an abundant number, since it is smaller than the sum of its proper divisors (5171335308).

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

2143556640 is a wasteful number, since it uses less digits than its factorization.

2143556640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1488602 (or 1488591 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The square root of 2143556640 is about 46298.5598048147. The cubic root of 2143556640 is about 1289.3722563201.

The spelling of 2143556640 in words is "two billion, one hundred forty-three million, five hundred fifty-six thousand, six hundred forty".