42908917 has 2 divisors, whose sum is σ = 42908918. Its totient is φ = 42908916.

The previous prime is 42908903. The next prime is 42908923. The reversal of 42908917 is 71980924.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41293476 + 1615441 = 6426^2 + 1271^2 .

It is a cyclic number.

It is not a de Polignac number, because 42908917 - 2¹⁵ = 42876149 is a prime.

It is a super-2 number, since 2×42908917² = 3682350316225778, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 42908917.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42908927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21454458 + 21454459.

It is an arithmetic number, because the mean of its divisors is an integer number (21454459).

Almost surely, 2^42908917 is an apocalyptic number.

It is an amenable number.

42908917 is a deficient number, since it is larger than the sum of its proper divisors (1).

42908917 is an equidigital number, since it uses as much as digits as its factorization.

42908917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 42908917 is about 6550.4898290128. The cubic root of 42908917 is about 350.0922668310.

The spelling of 42908917 in words is "forty-two million, nine hundred eight thousand, nine hundred seventeen".