42121421 has 8 divisors (see below), whose sum is σ = 42868224. Its totient is φ = 41380480.

The previous prime is 42121399. The next prime is 42121459. The reversal of 42121421 is 12412124.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 42121421 - 2⁶ = 42121357 is a prime.

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 42121421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42121481) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14525 + ... + 17181.

It is an arithmetic number, because the mean of its divisors is an integer number (5358528).

Almost surely, 2^42121421 is an apocalyptic number.

It is an amenable number.

42121421 is a deficient number, since it is larger than the sum of its proper divisors (746803).

42121421 is a wasteful number, since it uses less digits than its factorization.

42121421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2931.

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

The square root of 42121421 is about 6490.1017711589. The cubic root of 42121421 is about 347.9373125513.

Adding to 42121421 its reverse (12412124), we get a palindrome (54533545).

The spelling of 42121421 in words is "forty-two million, one hundred twenty-one thousand, four hundred twenty-one".