42789661 has 2 divisors, whose sum is σ = 42789662. Its totient is φ = 42789660.

The previous prime is 42789623. The next prime is 42789701. The reversal of 42789661 is 16698724.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39879225 + 2910436 = 6315^2 + 1706^2 .

It is a cyclic number.

It is not a de Polignac number, because 42789661 - 2¹⁵ = 42756893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42789161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21394830 + 21394831.

It is an arithmetic number, because the mean of its divisors is an integer number (21394831).

Almost surely, 2^42789661 is an apocalyptic number.

It is an amenable number.

42789661 is a deficient number, since it is larger than the sum of its proper divisors (1).

42789661 is an equidigital number, since it uses as much as digits as its factorization.

42789661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 43.

The square root of 42789661 is about 6541.3806646609. The cubic root of 42789661 is about 349.7676307954.

The spelling of 42789661 in words is "forty-two million, seven hundred eighty-nine thousand, six hundred sixty-one".