42221989 has 2 divisors, whose sum is σ = 42221990. Its totient is φ = 42221988.

The previous prime is 42221987. The next prime is 42222023. The reversal of 42221989 is 98912224.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36180225 + 6041764 = 6015^2 + 2458^2 .

It is a cyclic number.

It is not a de Polignac number, because 42221989 - 2¹ = 42221987 is a prime.

It is a super-2 number, since 2×42221989² = 3565392710232242, which contains 22 as substring.

Together with 42221987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42221987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21110994 + 21110995.

It is an arithmetic number, because the mean of its divisors is an integer number (21110995).

Almost surely, 2^42221989 is an apocalyptic number.

It is an amenable number.

42221989 is a deficient number, since it is larger than the sum of its proper divisors (1).

42221989 is an equidigital number, since it uses as much as digits as its factorization.

42221989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 37.

The square root of 42221989 is about 6497.8449504432. The cubic root of 42221989 is about 348.2140011304.

The spelling of 42221989 in words is "forty-two million, two hundred twenty-one thousand, nine hundred eighty-nine".