2121643864 has 16 divisors (see below), whose sum is σ = 3980241000. Its totient is φ = 1060246272.

The previous prime is 2121643859. The next prime is 2121643871. The reversal of 2121643864 is 4683461212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56089 + ... + 85960.

Almost surely, 2^2121643864 is an apocalyptic number.

It is an amenable number.

2121643864 is a deficient number, since it is larger than the sum of its proper divisors (1858597136).

2121643864 is a wasteful number, since it uses less digits than its factorization.

2121643864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143922 (or 143918 counting only the distinct ones).

The product of its digits is 55296, while the sum is 37.

The square root of 2121643864 is about 46061.3054960452. The cubic root of 2121643864 is about 1284.9636096222.

The spelling of 2121643864 in words is "two billion, one hundred twenty-one million, six hundred forty-three thousand, eight hundred sixty-four".