641528912025 has 189 divisors, whose sum is σ = 1270624596231. Its totient is φ = 321099655680.

The previous prime is 641528911979. The next prime is 641528912027. The reversal of 641528912025 is 520219825146.

The square root of 641528912025 is 800955.

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

641528912025 is a `hidden beast` number, since 6 + 415 + 28 + 9 + 1 + 202 + 5 = 666.

It can be written as a sum of positive squares in 13 ways, for example, as 91985430681 + 549543481344 = 303291^2 + 741312^2 .

It is not a de Polignac number, because 641528912025 - 2²³ = 641520523417 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (641528912027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 188 ways as a sum of consecutive naturals, for example, 1838191551 + ... + 1838191899.

Almost surely, 2^641528912025 is an apocalyptic number.

641528912025 is the 800955-th square number.

641528912025 is the 400478-th centered octagonal number.

It is an amenable number.

641528912025 is a deficient number, since it is larger than the sum of its proper divisors (629095684206).

641528912025 is an frugal number, since it uses more digits than its factorization.

641528912025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 760 (or 374 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The spelling of 641528912025 in words is "six hundred forty-one billion, five hundred twenty-eight million, nine hundred twelve thousand, twenty-five".