42902009 has 4 divisors (see below), whose sum is σ = 42927780. Its totient is φ = 42876240.

The previous prime is 42901993. The next prime is 42902021. The reversal of 42902009 is 90020924.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16605625 + 26296384 = 4075^2 + 5128^2 .

It is a cyclic number.

It is not a de Polignac number, because 42902009 - 2⁴ = 42901993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42902099) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10202 + ... + 13779.

It is an arithmetic number, because the mean of its divisors is an integer number (10731945).

Almost surely, 2^42902009 is an apocalyptic number.

It is an amenable number.

42902009 is a deficient number, since it is larger than the sum of its proper divisors (25771).

42902009 is a wasteful number, since it uses less digits than its factorization.

42902009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25770.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 42902009 is about 6549.9625189767. The cubic root of 42902009 is about 350.0734784505.

The spelling of 42902009 in words is "forty-two million, nine hundred two thousand, nine".