5640605021 has 4 divisors (see below), whose sum is σ = 5640775392. Its totient is φ = 5640434652.

The previous prime is 5640604987. The next prime is 5640605029. The reversal of 5640605021 is 1205060465.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5640605021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5640605029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17705 + ... + 107678.

It is an arithmetic number, because the mean of its divisors is an integer number (1410193848).

Almost surely, 2^5640605021 is an apocalyptic number.

It is an amenable number.

5640605021 is a deficient number, since it is larger than the sum of its proper divisors (170371).

5640605021 is a wasteful number, since it uses less digits than its factorization.

5640605021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170370.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 5640605021 is about 75103.9614201541. The cubic root of 5640605021 is about 1780.0897380378.

Adding to 5640605021 its reverse (1205060465), we get a palindrome (6845665486).

The spelling of 5640605021 in words is "five billion, six hundred forty million, six hundred five thousand, twenty-one".