291002639 has 4 divisors (see below), whose sum is σ = 291173256. Its totient is φ = 290832024.

The previous prime is 291002633. The next prime is 291002653. The reversal of 291002639 is 936200192.

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

It is a cyclic number.

It is not a de Polignac number, because 291002639 - 2¹⁶ = 290937103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (291002633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82724 + ... + 86169.

It is an arithmetic number, because the mean of its divisors is an integer number (72793314).

Almost surely, 2^291002639 is an apocalyptic number.

291002639 is a deficient number, since it is larger than the sum of its proper divisors (170617).

291002639 is a wasteful number, since it uses less digits than its factorization.

291002639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170616.

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 291002639 is about 17058.7994595165. The cubic root of 291002639 is about 662.6725419347.

The spelling of 291002639 in words is "two hundred ninety-one million, two thousand, six hundred thirty-nine".