445640621 has 2 divisors, whose sum is σ = 445640622. Its totient is φ = 445640620.

The previous prime is 445640609. The next prime is 445640623. The reversal of 445640621 is 126046544.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 322741225 + 122899396 = 17965^2 + 11086^2 .

It is a cyclic number.

It is not a de Polignac number, because 445640621 - 2⁶ = 445640557 is a prime.

It is a Sophie Germain prime.

Together with 445640623, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (445640623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 222820310 + 222820311.

It is an arithmetic number, because the mean of its divisors is an integer number (222820311).

Almost surely, 2^445640621 is an apocalyptic number.

It is an amenable number.

445640621 is a deficient number, since it is larger than the sum of its proper divisors (1).

445640621 is an equidigital number, since it uses as much as digits as its factorization.

445640621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23040, while the sum is 32.

The square root of 445640621 is about 21110.2018228154. The cubic root of 445640621 is about 763.8268552426.

The spelling of 445640621 in words is "four hundred forty-five million, six hundred forty thousand, six hundred twenty-one".