6445826021 has 2 divisors, whose sum is σ = 6445826022. Its totient is φ = 6445826020.

The previous prime is 6445826003. The next prime is 6445826041. The reversal of 6445826021 is 1206285446.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4701844900 + 1743981121 = 68570^2 + 41761^2 .

It is a cyclic number.

It is not a de Polignac number, because 6445826021 - 2¹⁴ = 6445809637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6445826041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3222913010 + 3222913011.

It is an arithmetic number, because the mean of its divisors is an integer number (3222913011).

Almost surely, 2^6445826021 is an apocalyptic number.

It is an amenable number.

6445826021 is a deficient number, since it is larger than the sum of its proper divisors (1).

6445826021 is an equidigital number, since it uses as much as digits as its factorization.

6445826021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 92160, while the sum is 38.

The square root of 6445826021 is about 80285.9017574069. The cubic root of 6445826021 is about 1861.0563642299.

The spelling of 6445826021 in words is "six billion, four hundred forty-five million, eight hundred twenty-six thousand, twenty-one".