42121223125 has 10 divisors (see below), whose sum is σ = 52634681198. Its totient is φ = 33696978000.

The previous prime is 42121223093. The next prime is 42121223129. The reversal of 42121223125 is 52132212124.

It can be written as a sum of positive squares in 5 ways, for example, as 7124541649 + 34996681476 = 84407^2 + 187074^2 .

It is not a de Polignac number, because 42121223125 - 2⁵ = 42121223093 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42121223125.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42121223129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 33696354 + ... + 33697603.

Almost surely, 2^42121223125 is an apocalyptic number.

It is an amenable number.

42121223125 is a deficient number, since it is larger than the sum of its proper divisors (10513458073).

42121223125 is an frugal number, since it uses more digits than its factorization.

42121223125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67393977 (or 67393962 counting only the distinct ones).

The product of its digits is 1920, while the sum is 25.

Adding to 42121223125 its reverse (52132212124), we get a palindrome (94253435249).

The spelling of 42121223125 in words is "forty-two billion, one hundred twenty-one million, two hundred twenty-three thousand, one hundred twenty-five".