442681021 has 2 divisors, whose sum is σ = 442681022. Its totient is φ = 442681020.

The previous prime is 442680991. The next prime is 442681033. The reversal of 442681021 is 120186244.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 415588996 + 27092025 = 20386^2 + 5205^2 .

It is a cyclic number.

It is not a de Polignac number, because 442681021 - 2⁷ = 442680893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (442681051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 221340510 + 221340511.

It is an arithmetic number, because the mean of its divisors is an integer number (221340511).

Almost surely, 2^442681021 is an apocalyptic number.

It is an amenable number.

442681021 is a deficient number, since it is larger than the sum of its proper divisors (1).

442681021 is an equidigital number, since it uses as much as digits as its factorization.

442681021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 442681021 is about 21039.9862404898. The cubic root of 442681021 is about 762.1321825744.

The spelling of 442681021 in words is "four hundred forty-two million, six hundred eighty-one thousand, twenty-one".