641981402 has 8 divisors (see below), whose sum is σ = 963081012. Its totient is φ = 320954400.

The previous prime is 641981401. The next prime is 641981407. The reversal of 641981402 is 204189146.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 490666801 + 151314601 = 22151^2 + 12301^2 .

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

It is not an unprimeable number, because it can be changed into a prime (641981401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19952 + ... + 41012.

Almost surely, 2^641981402 is an apocalyptic number.

641981402 is a deficient number, since it is larger than the sum of its proper divisors (321099610).

641981402 is a wasteful number, since it uses less digits than its factorization.

641981402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36304.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 641981402 is about 25337.3519137261. The cubic root of 641981402 is about 862.6622933975.

The spelling of 641981402 in words is "six hundred forty-one million, nine hundred eighty-one thousand, four hundred two".