42121523 has 4 divisors (see below), whose sum is σ = 42149160. Its totient is φ = 42093888.

The previous prime is 42121501. The next prime is 42121549. The reversal of 42121523 is 32512124.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 42121523 - 2⁶ = 42121459 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42121495 and 42121504.

It is not an unprimeable number, because it can be changed into a prime (42120523) 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, 11390 + ... + 14627.

It is an arithmetic number, because the mean of its divisors is an integer number (10537290).

Almost surely, 2^42121523 is an apocalyptic number.

42121523 is a deficient number, since it is larger than the sum of its proper divisors (27637).

42121523 is a wasteful number, since it uses less digits than its factorization.

42121523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27636.

The product of its digits is 480, while the sum is 20.

The square root of 42121523 is about 6490.1096292744. The cubic root of 42121523 is about 347.9375934026.

Adding to 42121523 its reverse (32512124), we get a palindrome (74633647).

The spelling of 42121523 in words is "forty-two million, one hundred twenty-one thousand, five hundred twenty-three".