2638443645 has 64 divisors (see below), whose sum is σ = 4983264000. Its totient is φ = 1320738048.

The previous prime is 2638443637. The next prime is 2638443671. The reversal of 2638443645 is 5463448362.

2638443645 is a `hidden beast` number, since 2 + 638 + 4 + 4 + 3 + 6 + 4 + 5 = 666.

It is not a de Polignac number, because 2638443645 - 2³ = 2638443637 is a prime.

It is a super-2 number, since 2×2638443645² = 13922769735681772050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 2638443645.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 274867 + ... + 284303.

It is an arithmetic number, because the mean of its divisors is an integer number (77863500).

Almost surely, 2^2638443645 is an apocalyptic number.

It is an amenable number.

2638443645 is a deficient number, since it is larger than the sum of its proper divisors (2344820355).

2638443645 is a wasteful number, since it uses less digits than its factorization.

2638443645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9579 (or 9573 counting only the distinct ones).

The product of its digits is 1658880, while the sum is 45.

The square root of 2638443645 is about 51365.7828228092. The cubic root of 2638443645 is about 1381.8129998933.

The spelling of 2638443645 in words is "two billion, six hundred thirty-eight million, four hundred forty-three thousand, six hundred forty-five".