2661643642 has 32 divisors (see below), whose sum is σ = 4676544000. Its totient is φ = 1135656144.

The previous prime is 2661643619. The next prime is 2661643657. The reversal of 2661643642 is 2463461662.

It is a junction number, because it is equal to n+sod(n) for n = 2661643595 and 2661643604.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 148623 + ... + 165565.

It is an arithmetic number, because the mean of its divisors is an integer number (146142000).

Almost surely, 2^2661643642 is an apocalyptic number.

2661643642 is a deficient number, since it is larger than the sum of its proper divisors (2014900358).

2661643642 is a wasteful number, since it uses less digits than its factorization.

2661643642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17195 (or 17181 counting only the distinct ones).

The product of its digits is 248832, while the sum is 40.

The square root of 2661643642 is about 51591.1197978877. The cubic root of 2661643642 is about 1385.8513087436.

The spelling of 2661643642 in words is "two billion, six hundred sixty-one million, six hundred forty-three thousand, six hundred forty-two".