641602081 has 8 divisors (see below), whose sum is σ = 646746984. Its totient is φ = 636478080.

The previous prime is 641602057. The next prime is 641602109. The reversal of 641602081 is 180206146.

It can be written as a sum of positive squares in 4 ways, for example, as 67568400 + 574033681 = 8220^2 + 23959^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-641602081 is a prime.

It is a super-2 number, since 2×641602081² = 823306460687061122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641602001) 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, 59571 + ... + 69511.

It is an arithmetic number, because the mean of its divisors is an integer number (80843373).

Almost surely, 2^641602081 is an apocalyptic number.

It is an amenable number.

641602081 is a deficient number, since it is larger than the sum of its proper divisors (5144903).

641602081 is a wasteful number, since it uses less digits than its factorization.

641602081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10451.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 641602081 is about 25329.8653964051. The cubic root of 641602081 is about 862.4923557679.

The spelling of 641602081 in words is "six hundred forty-one million, six hundred two thousand, eighty-one".