290640509 has 4 divisors (see below), whose sum is σ = 290921280. Its totient is φ = 290359740.

The previous prime is 290640487. The next prime is 290640533. The reversal of 290640509 is 905046092.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-290640509 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 (290640599) 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, 138827 + ... + 140904.

It is an arithmetic number, because the mean of its divisors is an integer number (72730320).

Almost surely, 2^290640509 is an apocalyptic number.

It is an amenable number.

290640509 is a deficient number, since it is larger than the sum of its proper divisors (280771).

290640509 is a wasteful number, since it uses less digits than its factorization.

290640509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280770.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 290640509 is about 17048.1819851854. The cubic root of 290640509 is about 662.3975464683.

The spelling of 290640509 in words is "two hundred ninety million, six hundred forty thousand, five hundred nine".