640771373 has 8 divisors (see below), whose sum is σ = 699973056. Its totient is φ = 581728000.

The previous prime is 640771367. The next prime is 640771403. The reversal of 640771373 is 373177046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640771373 - 2⁶ = 640771309 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 (640771673) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31028 + ... + 47373.

It is an arithmetic number, because the mean of its divisors is an integer number (87496632).

Almost surely, 2^640771373 is an apocalyptic number.

It is an amenable number.

640771373 is a deficient number, since it is larger than the sum of its proper divisors (59201683).

640771373 is a wasteful number, since it uses less digits than its factorization.

640771373 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79155.

The product of its (nonzero) digits is 74088, while the sum is 38.

The square root of 640771373 is about 25313.4622878815. The cubic root of 640771373 is about 862.1199604978.

The spelling of 640771373 in words is "six hundred forty million, seven hundred seventy-one thousand, three hundred seventy-three".