2181021652 has 24 divisors (see below), whose sum is σ = 3923861760. Its totient is φ = 1060226400.

The previous prime is 2181021649. The next prime is 2181021659. The reversal of 2181021652 is 2561201812.

It is a self number, because there is not a number n which added to its sum of digits gives 2181021652.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2181021659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10027 + ... + 66802.

It is an arithmetic number, because the mean of its divisors is an integer number (163494240).

Almost surely, 2^2181021652 is an apocalyptic number.

It is an amenable number.

2181021652 is a deficient number, since it is larger than the sum of its proper divisors (1742840108).

2181021652 is a wasteful number, since it uses less digits than its factorization.

2181021652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77031 (or 77029 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 2181021652 is about 46701.4095290495. The cubic root of 2181021652 is about 1296.8407808551.

The spelling of 2181021652 in words is "two billion, one hundred eighty-one million, twenty-one thousand, six hundred fifty-two".