821746945 has 8 divisors (see below), whose sum is σ = 986290344. Its totient is φ = 657268224.

The previous prime is 821746943. The next prime is 821746973. The reversal of 821746945 is 549647128.

821746945 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 4 ways, for example, as 172975104 + 648771841 = 13152^2 + 25471^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 821746945 - 2¹ = 821746943 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 821746895 and 821746904.

It is not an unprimeable number, because it can be changed into a prime (821746943) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18577 + ... + 44593.

It is an arithmetic number, because the mean of its divisors is an integer number (123286293).

Almost surely, 2^821746945 is an apocalyptic number.

It is an amenable number.

821746945 is a deficient number, since it is larger than the sum of its proper divisors (164543399).

821746945 is a wasteful number, since it uses less digits than its factorization.

821746945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32339.

The product of its digits is 483840, while the sum is 46.

The square root of 821746945 is about 28666.1288806145. The cubic root of 821746945 is about 936.6543751351.

The spelling of 821746945 in words is "eight hundred twenty-one million, seven hundred forty-six thousand, nine hundred forty-five".