42221639 has 4 divisors (see below), whose sum is σ = 42937320. Its totient is φ = 41505960.

The previous prime is 42221633. The next prime is 42221681. The reversal of 42221639 is 93612224.

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 42221639 - 2⁴ = 42221623 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 (42221633) 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, 357752 + ... + 357869.

It is an arithmetic number, because the mean of its divisors is an integer number (10734330).

Almost surely, 2^42221639 is an apocalyptic number.

42221639 is a deficient number, since it is larger than the sum of its proper divisors (715681).

42221639 is an equidigital number, since it uses as much as digits as its factorization.

42221639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 715680.

The product of its digits is 5184, while the sum is 29.

The square root of 42221639 is about 6497.8180183812. The cubic root of 42221639 is about 348.2130389521.

The spelling of 42221639 in words is "forty-two million, two hundred twenty-one thousand, six hundred thirty-nine".