42452021 has 4 divisors (see below), whose sum is σ = 42929100. Its totient is φ = 41974944.

The previous prime is 42451973. The next prime is 42452029. The reversal of 42452021 is 12025424.

It is a happy number.

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 13140625 + 29311396 = 3625^2 + 5414^2 .

It is a cyclic number.

It is not a de Polignac number, because 42452021 - 2⁶ = 42451957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42451984 and 42452002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42452029) 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, 238406 + ... + 238583.

It is an arithmetic number, because the mean of its divisors is an integer number (10732275).

Almost surely, 2^42452021 is an apocalyptic number.

It is an amenable number.

42452021 is a deficient number, since it is larger than the sum of its proper divisors (477079).

42452021 is an equidigital number, since it uses as much as digits as its factorization.

42452021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 477078.

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 42452021 is about 6515.5215447422. The cubic root of 42452021 is about 348.8452309489.

Adding to 42452021 its reverse (12025424), we get a palindrome (54477445).

The spelling of 42452021 in words is "forty-two million, four hundred fifty-two thousand, twenty-one".