42512221 has 4 divisors (see below), whose sum is σ = 42557152. Its totient is φ = 42467292.

The previous prime is 42512219. The next prime is 42512269. The reversal of 42512221 is 12221524.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 42512221 - 2¹ = 42512219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42512621) 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, 21015 + ... + 22948.

It is an arithmetic number, because the mean of its divisors is an integer number (10639288).

Almost surely, 2^42512221 is an apocalyptic number.

It is an amenable number.

42512221 is a deficient number, since it is larger than the sum of its proper divisors (44931).

42512221 is an equidigital number, since it uses as much as digits as its factorization.

42512221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44930.

The product of its digits is 320, while the sum is 19.

The square root of 42512221 is about 6520.1396457438. The cubic root of 42512221 is about 349.0100488892.

Adding to 42512221 its reverse (12221524), we get a palindrome (54733745).

It can be divided in two parts, 4 and 2512221, that added together give a square (2512225 = 1585²).

The spelling of 42512221 in words is "forty-two million, five hundred twelve thousand, two hundred twenty-one".