42221661 has 4 divisors (see below), whose sum is σ = 56295552. Its totient is φ = 28147772.

The previous prime is 42221633. The next prime is 42221681. The reversal of 42221661 is 16612224.

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 42221661 - 2¹⁰ = 42220637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42221611) 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, 7036941 + ... + 7036946.

It is an arithmetic number, because the mean of its divisors is an integer number (14073888).

Almost surely, 2^42221661 is an apocalyptic number.

It is an amenable number.

42221661 is a deficient number, since it is larger than the sum of its proper divisors (14073891).

42221661 is a wasteful number, since it uses less digits than its factorization.

42221661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14073890.

The product of its digits is 1152, while the sum is 24.

The square root of 42221661 is about 6497.8197112570. The cubic root of 42221661 is about 348.2130994320.

Adding to 42221661 its reverse (16612224), we get a palindrome (58833885).

The spelling of 42221661 in words is "forty-two million, two hundred twenty-one thousand, six hundred sixty-one".