821606280625 has 45 divisors (see below), whose sum is σ = 1112128312053. Its totient is φ = 606507096000.

The previous prime is 821606280613. The next prime is 821606280641. The reversal of 821606280625 is 526082606128.

The square root of 821606280625 is 906425.

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

It can be written as a sum of positive squares in 22 ways, for example, as 601172274609 + 220434006016 = 775353^2 + 469504^2 .

It is not a de Polignac number, because 821606280625 - 2⁷ = 821606280497 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 294586731 + ... + 294589519.

Almost surely, 2^821606280625 is an apocalyptic number.

821606280625 is the 906425-th square number.

821606280625 is the 453213-rd centered octagonal number.

It is an amenable number.

821606280625 is a deficient number, since it is larger than the sum of its proper divisors (290522031428).

821606280625 is an frugal number, since it uses more digits than its factorization.

821606280625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5624 (or 2807 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 46.

The spelling of 821606280625 in words is "eight hundred twenty-one billion, six hundred six million, two hundred eighty thousand, six hundred twenty-five".