42312121 has 2 divisors, whose sum is σ = 42312122. Its totient is φ = 42312120.

The previous prime is 42312103. The next prime is 42312143. The reversal of 42312121 is 12121324.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 34810000 + 7502121 = 5900^2 + 2739^2 .

It is a cyclic number.

It is not a de Polignac number, because 42312121 - 2¹³ = 42303929 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 42312095 and 42312104.

It is not a weakly prime, because it can be changed into another prime (42312821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21156060 + 21156061.

It is an arithmetic number, because the mean of its divisors is an integer number (21156061).

Almost surely, 2^42312121 is an apocalyptic number.

It is an amenable number.

42312121 is a deficient number, since it is larger than the sum of its proper divisors (1).

42312121 is an equidigital number, since it uses as much as digits as its factorization.

42312121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96, while the sum is 16.

The square root of 42312121 is about 6504.7767832571. The cubic root of 42312121 is about 348.4616044818.

Adding to 42312121 its reverse (12121324), we get a palindrome (54433445).

It can be divided in two parts, 423 and 12121, that added together give a square (12544 = 112²).

The spelling of 42312121 in words is "forty-two million, three hundred twelve thousand, one hundred twenty-one".