821863001 has 4 divisors (see below), whose sum is σ = 822108900. Its totient is φ = 821617104.

The previous prime is 821862989. The next prime is 821863019. The reversal of 821863001 is 100368128.

821863001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 703575625 + 118287376 = 26525^2 + 10876^2 .

It is a cyclic number.

It is not a de Polignac number, because 821863001 - 2²² = 817668697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (821863051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117866 + ... + 124643.

It is an arithmetic number, because the mean of its divisors is an integer number (205527225).

Almost surely, 2^821863001 is an apocalyptic number.

It is an amenable number.

821863001 is a deficient number, since it is larger than the sum of its proper divisors (245899).

821863001 is a wasteful number, since it uses less digits than its factorization.

821863001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245898.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 821863001 is about 28668.1530796806. The cubic root of 821863001 is about 936.6984678832.

The spelling of 821863001 in words is "eight hundred twenty-one million, eight hundred sixty-three thousand, one".