640219571 has 4 divisors (see below), whose sum is σ = 653841312. Its totient is φ = 626597832.

The previous prime is 640219537. The next prime is 640219589. The reversal of 640219571 is 175912046.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 175912046 = 2 ⋅87956023.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640219571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640219771) 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, 6810800 + ... + 6810893.

It is an arithmetic number, because the mean of its divisors is an integer number (163460328).

Almost surely, 2^640219571 is an apocalyptic number.

640219571 is a deficient number, since it is larger than the sum of its proper divisors (13621741).

640219571 is a wasteful number, since it uses less digits than its factorization.

640219571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13621740.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 640219571 is about 25302.5605621249. The cubic root of 640219571 is about 861.8724171152.

The spelling of 640219571 in words is "six hundred forty million, two hundred nineteen thousand, five hundred seventy-one".