640378193 has 8 divisors (see below), whose sum is σ = 788157888. Its totient is φ = 506672784.

The previous prime is 640378169. The next prime is 640378217. The reversal of 640378193 is 391873046.

It is an interprime number because it is at equal distance from previous prime (640378169) and next prime (640378217).

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 640378193 - 2¹⁰ = 640377169 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 640378193.

It is not an unprimeable number, because it can be changed into a prime (640378133) 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, 3518471 + ... + 3518652.

It is an arithmetic number, because the mean of its divisors is an integer number (98519736).

Almost surely, 2^640378193 is an apocalyptic number.

It is an amenable number.

640378193 is a deficient number, since it is larger than the sum of its proper divisors (147779695).

640378193 is a wasteful number, since it uses less digits than its factorization.

640378193 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7037143.

The product of its (nonzero) digits is 108864, while the sum is 41.

The square root of 640378193 is about 25305.6948728937. The cubic root of 640378193 is about 861.9435909455.

The spelling of 640378193 in words is "six hundred forty million, three hundred seventy-eight thousand, one hundred ninety-three".