641256577 has 8 divisors (see below), whose sum is σ = 692945064. Its totient is φ = 589905408.

The previous prime is 641256547. The next prime is 641256587. The reversal of 641256577 is 775652146.

It can be written as a sum of positive squares in 4 ways, for example, as 290668401 + 350588176 = 17049^2 + 18724^2 .

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 641256577 - 2¹¹ = 641254529 is a prime.

It is a super-2 number, since 2×641256577² = 822419995091513858, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641256547) 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, 80368 + ... + 87985.

It is an arithmetic number, because the mean of its divisors is an integer number (86618133).

Almost surely, 2^641256577 is an apocalyptic number.

It is an amenable number.

641256577 is a deficient number, since it is larger than the sum of its proper divisors (51688487).

641256577 is a wasteful number, since it uses less digits than its factorization.

641256577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168659.

The product of its digits is 352800, while the sum is 43.

The square root of 641256577 is about 25323.0443864872. The cubic root of 641256577 is about 862.3375100185.

It can be divided in two parts, 64 and 1256577, that added together give a square (1256641 = 1121²).

The spelling of 641256577 in words is "six hundred forty-one million, two hundred fifty-six thousand, five hundred seventy-seven".