42728117 has 2 divisors, whose sum is σ = 42728118. Its totient is φ = 42728116.

The previous prime is 42728087. The next prime is 42728143. The reversal of 42728117 is 71182724.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25745476 + 16982641 = 5074^2 + 4121^2 .

It is a cyclic number.

It is not a de Polignac number, because 42728117 - 2¹⁰ = 42727093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42728617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21364058 + 21364059.

It is an arithmetic number, because the mean of its divisors is an integer number (21364059).

Almost surely, 2^42728117 is an apocalyptic number.

It is an amenable number.

42728117 is a deficient number, since it is larger than the sum of its proper divisors (1).

42728117 is an equidigital number, since it uses as much as digits as its factorization.

42728117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6272, while the sum is 32.

The square root of 42728117 is about 6536.6747662707. The cubic root of 42728117 is about 349.5998610812.

The spelling of 42728117 in words is "forty-two million, seven hundred twenty-eight thousand, one hundred seventeen".