2128021644 has 24 divisors (see below), whose sum is σ = 5674724608. Its totient is φ = 608006160.

The previous prime is 2128021591. The next prime is 2128021697. The reversal of 2128021644 is 4461208212.

It is an interprime number because it is at equal distance from previous prime (2128021591) and next prime (2128021697).

It is a super-2 number, since 2×2128021644² = 9056952234664925472, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12666712 + ... + 12666879.

Almost surely, 2^2128021644 is an apocalyptic number.

It is an amenable number.

2128021644 is an abundant number, since it is smaller than the sum of its proper divisors (3546702964).

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

2128021644 is a wasteful number, since it uses less digits than its factorization.

2128021644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25333605 (or 25333603 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 30.

The square root of 2128021644 is about 46130.4849746889. The cubic root of 2128021644 is about 1286.2498790848.

Adding to 2128021644 its reverse (4461208212), we get a palindrome (6589229856).

It can be divided in two parts, 21280 and 21644, that added together give a palindrome (42924).

The spelling of 2128021644 in words is "two billion, one hundred twenty-eight million, twenty-one thousand, six hundred forty-four".