3634642640 has 20 divisors (see below), whose sum is σ = 8450544324. Its totient is φ = 1453857024.

The previous prime is 3634642637. The next prime is 3634642651. The reversal of 3634642640 is 462464363.

It can be written as a sum of positive squares in 2 ways, for example, as 1996659856 + 1637982784 = 44684^2 + 40472^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 3634642594 and 3634642603.

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, 22716437 + ... + 22716596.

Almost surely, 2^3634642640 is an apocalyptic number.

It is an amenable number.

3634642640 is an abundant number, since it is smaller than the sum of its proper divisors (4815901684).

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

3634642640 is a wasteful number, since it uses less digits than its factorization.

3634642640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45433046 (or 45433040 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 38.

The square root of 3634642640 is about 60287.9974787685. The cubic root of 3634642640 is about 1537.5192871311.

The spelling of 3634642640 in words is "three billion, six hundred thirty-four million, six hundred forty-two thousand, six hundred forty".