641226857 has 4 divisors (see below), whose sum is σ = 642842436. Its totient is φ = 639611280.

The previous prime is 641226853. The next prime is 641226931. The reversal of 641226857 is 758622146.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 346108816 + 295118041 = 18604^2 + 17179^2 .

It is a cyclic number.

It is not a de Polignac number, because 641226857 - 2² = 641226853 is a prime.

It is a super-2 number, since 2×641226857² = 822343764276196898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641226853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 807194 + ... + 807987.

It is an arithmetic number, because the mean of its divisors is an integer number (160710609).

Almost surely, 2^641226857 is an apocalyptic number.

It is an amenable number.

641226857 is a deficient number, since it is larger than the sum of its proper divisors (1615579).

641226857 is a wasteful number, since it uses less digits than its factorization.

641226857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1615578.

The product of its digits is 161280, while the sum is 41.

The square root of 641226857 is about 25322.4575624089. The cubic root of 641226857 is about 862.3241877033.

The spelling of 641226857 in words is "six hundred forty-one million, two hundred twenty-six thousand, eight hundred fifty-seven".