42669721 has 2 divisors, whose sum is σ = 42669722. Its totient is φ = 42669720.

The previous prime is 42669691. The next prime is 42669797. The reversal of 42669721 is 12796624.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32035600 + 10634121 = 5660^2 + 3261^2 .

It is a cyclic number.

It is not a de Polignac number, because 42669721 - 2⁵ = 42669689 is a prime.

It is not a weakly prime, because it can be changed into another prime (42669521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21334860 + 21334861.

It is an arithmetic number, because the mean of its divisors is an integer number (21334861).

Almost surely, 2^42669721 is an apocalyptic number.

It is an amenable number.

42669721 is a deficient number, since it is larger than the sum of its proper divisors (1).

42669721 is an equidigital number, since it uses as much as digits as its factorization.

42669721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 37.

The square root of 42669721 is about 6532.2064419306. The cubic root of 42669721 is about 349.4405238391.

The spelling of 42669721 in words is "forty-two million, six hundred sixty-nine thousand, seven hundred twenty-one".