442012121 has 4 divisors (see below), whose sum is σ = 468012852. Its totient is φ = 416011392.

The previous prime is 442012117. The next prime is 442012139. The reversal of 442012121 is 121210244.

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 133518025 + 308494096 = 11555^2 + 17564^2 .

It is a cyclic number.

It is not a de Polignac number, because 442012121 - 2² = 442012117 is a prime.

It is a super-2 number, since 2×442012121² = 390749430221837282, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 26000713 = 442012121 / (4 + 4 + 2 + 0 + 1 + 2 + 1 + 2 + 1).

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 442012121.

It is not an unprimeable number, because it can be changed into a prime (442012141) 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, 13000340 + ... + 13000373.

It is an arithmetic number, because the mean of its divisors is an integer number (117003213).

Almost surely, 2^442012121 is an apocalyptic number.

It is an amenable number.

442012121 is a deficient number, since it is larger than the sum of its proper divisors (26000731).

442012121 is a wasteful number, since it uses less digits than its factorization.

442012121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26000730.

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 442012121 is about 21024.0843082404. The cubic root of 442012121 is about 761.7481233412.

Adding to 442012121 its reverse (121210244), we get a palindrome (563222365).

The spelling of 442012121 in words is "four hundred forty-two million, twelve thousand, one hundred twenty-one".