826381021 has 4 divisors (see below), whose sum is σ = 830946844. Its totient is φ = 821815200.

The previous prime is 826381019. The next prime is 826381027. The reversal of 826381021 is 120183628.

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 339075396 + 487305625 = 18414^2 + 22075^2 .

It is a cyclic number.

It is not a de Polignac number, because 826381021 - 2¹ = 826381019 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (826381027) 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, 2282640 + ... + 2283001.

It is an arithmetic number, because the mean of its divisors is an integer number (207736711).

Almost surely, 2^826381021 is an apocalyptic number.

It is an amenable number.

826381021 is a deficient number, since it is larger than the sum of its proper divisors (4565823).

826381021 is a wasteful number, since it uses less digits than its factorization.

826381021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4565822.

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 826381021 is about 28746.8436702188. The cubic root of 826381021 is about 938.4117668628.

The spelling of 826381021 in words is "eight hundred twenty-six million, three hundred eighty-one thousand, twenty-one".