821670425 has 6 divisors (see below), whose sum is σ = 1018871358. Its totient is φ = 657336320.

The previous prime is 821670419. The next prime is 821670467. The reversal of 821670425 is 524076128.

821670425 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 6739216 + 814931209 = 2596^2 + 28547^2 .

It is not a de Polignac number, because 821670425 - 2⁶ = 821670361 is a prime.

It is a super-3 number, since 3×821670425³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16433384 + ... + 16433433.

It is an arithmetic number, because the mean of its divisors is an integer number (169811893).

Almost surely, 2^821670425 is an apocalyptic number.

It is an amenable number.

821670425 is a deficient number, since it is larger than the sum of its proper divisors (197200933).

821670425 is a wasteful number, since it uses less digits than its factorization.

821670425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32866827 (or 32866822 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 35.

The square root of 821670425 is about 28664.7941733409. The cubic root of 821670425 is about 936.6253008894.

The spelling of 821670425 in words is "eight hundred twenty-one million, six hundred seventy thousand, four hundred twenty-five".