42445421 has 8 divisors (see below), whose sum is σ = 43530264. Its totient is φ = 41371200.

The previous prime is 42445409. The next prime is 42445451. The reversal of 42445421 is 12454424.

It can be written as a sum of positive squares in 4 ways, for example, as 13225 + 42432196 = 115^2 + 6514^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 42445421 - 2¹⁸ = 42183277 is a prime.

It is a super-2 number, since 2×42445421² = 3603227527734482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42445451) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5771 + ... + 10871.

It is an arithmetic number, because the mean of its divisors is an integer number (5441283).

Almost surely, 2^42445421 is an apocalyptic number.

It is an amenable number.

42445421 is a deficient number, since it is larger than the sum of its proper divisors (1084843).

42445421 is a wasteful number, since it uses less digits than its factorization.

42445421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5311.

The product of its digits is 5120, while the sum is 26.

The square root of 42445421 is about 6515.0150421929. The cubic root of 42445421 is about 348.8271517323.

Adding to 42445421 its reverse (12454424), we get a palindrome (54899845).

The spelling of 42445421 in words is "forty-two million, four hundred forty-five thousand, four hundred twenty-one".