641378 has 16 divisors (see below), whose sum is σ = 1022976. Its totient is φ = 300960.

The previous prime is 641371. The next prime is 641387. The reversal of 641378 is 873146.

It is a super-2 number, since 2×641378² = 822731477768, which contains 22 as substring.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 641378.

It is not an unprimeable number, because it can be changed into a prime (641371) by changing a digit.

641378 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3263 + ... + 3453.

It is an arithmetic number, because the mean of its divisors is an integer number (63936).

2⁶⁴¹³⁷⁸ is an apocalyptic number.

641378 is a deficient number, since it is larger than the sum of its proper divisors (381598).

641378 is a wasteful number, since it uses less digits than its factorization.

641378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289.

The product of its digits is 4032, while the sum is 29.

The square root of 641378 is about 800.8607869037. The cubic root of 641378 is about 86.2391934931.

The spelling of 641378 in words is "six hundred forty-one thousand, three hundred seventy-eight".