825644641 has 2 divisors, whose sum is σ = 825644642. Its totient is φ = 825644640.

The previous prime is 825644621. The next prime is 825644657. The reversal of 825644641 is 146446528.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 572166400 + 253478241 = 23920^2 + 15921^2 .

It is a cyclic number.

It is not a de Polignac number, because 825644641 - 2¹¹ = 825642593 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 825644594 and 825644603.

It is not a weakly prime, because it can be changed into another prime (825644621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 412822320 + 412822321.

It is an arithmetic number, because the mean of its divisors is an integer number (412822321).

Almost surely, 2^825644641 is an apocalyptic number.

It is an amenable number.

825644641 is a deficient number, since it is larger than the sum of its proper divisors (1).

825644641 is an equidigital number, since it uses as much as digits as its factorization.

825644641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 184320, while the sum is 40.

The square root of 825644641 is about 28734.0328008444. The cubic root of 825644641 is about 938.1329475301.

The spelling of 825644641 in words is "eight hundred twenty-five million, six hundred forty-four thousand, six hundred forty-one".