402442121 has 4 divisors (see below), whose sum is σ = 402482244. Its totient is φ = 402402000.

The previous prime is 402442067. The next prime is 402442141. The reversal of 402442121 is 121244204.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 65205625 + 337236496 = 8075^2 + 18364^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-402442121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 402442093 and 402442102.

It is not an unprimeable number, because it can be changed into a prime (402442141) 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, 9971 + ... + 30071.

It is an arithmetic number, because the mean of its divisors is an integer number (100620561).

Almost surely, 2^402442121 is an apocalyptic number.

It is an amenable number.

402442121 is a deficient number, since it is larger than the sum of its proper divisors (40123).

402442121 is a wasteful number, since it uses less digits than its factorization.

402442121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40122.

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 402442121 is about 20060.9601215894. The cubic root of 402442121 is about 738.3027335681.

Adding to 402442121 its reverse (121244204), we get a palindrome (523686325).

The spelling of 402442121 in words is "four hundred two million, four hundred forty-two thousand, one hundred twenty-one".