641657071225 has 9 divisors (see below), whose sum is σ = 795659734767. Its totient is φ = 513322452840.

The previous prime is 641657071199. The next prime is 641657071243. The reversal of 641657071225 is 522170756146.

The square root of 641657071225 is 801035.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 230996545641 + 410660525584 = 480621^2 + 640828^2 .

It is not a de Polignac number, because 641657071225 - 2⁹ = 641657070713 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3925072 + ... + 4085278.

Almost surely, 2^641657071225 is an apocalyptic number.

641657071225 is the 801035-th square number.

641657071225 is the 400518-th centered octagonal number.

It is an amenable number.

641657071225 is a deficient number, since it is larger than the sum of its proper divisors (154002663542).

641657071225 is an frugal number, since it uses more digits than its factorization.

641657071225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320424 (or 160212 counting only the distinct ones).

The product of its (nonzero) digits is 705600, while the sum is 46.

The spelling of 641657071225 in words is "six hundred forty-one billion, six hundred fifty-seven million, seventy-one thousand, two hundred twenty-five".