42991747 has 2 divisors, whose sum is σ = 42991748. Its totient is φ = 42991746.

The previous prime is 42991733. The next prime is 42991769. The reversal of 42991747 is 74719924.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42991747 - 2¹¹ = 42989699 is a prime.

It is a super-2 number, since 2×42991747² = 3696580620224018, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (42991777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21495873 + 21495874.

It is an arithmetic number, because the mean of its divisors is an integer number (21495874).

Almost surely, 2^42991747 is an apocalyptic number.

42991747 is a deficient number, since it is larger than the sum of its proper divisors (1).

42991747 is an equidigital number, since it uses as much as digits as its factorization.

42991747 is an evil number, because the sum of its binary digits is even.

The product of its digits is 127008, while the sum is 43.

The square root of 42991747 is about 6556.8092087539. The cubic root of 42991747 is about 350.3173910044.

The spelling of 42991747 in words is "forty-two million, nine hundred ninety-one thousand, seven hundred forty-seven".