509491001 has 4 divisors (see below), whose sum is σ = 509546532. Its totient is φ = 509435472.

The previous prime is 509490997. The next prime is 509491007. The reversal of 509491001 is 100194905.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 100194905 = 5 ⋅20038981.

It can be written as a sum of positive squares in 2 ways, for example, as 214476025 + 295014976 = 14645^2 + 17176^2 .

It is a cyclic number.

It is not a de Polignac number, because 509491001 - 2² = 509490997 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (509491007) 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, 10370 + ... + 33563.

It is an arithmetic number, because the mean of its divisors is an integer number (127386633).

Almost surely, 2^509491001 is an apocalyptic number.

It is an amenable number.

509491001 is a deficient number, since it is larger than the sum of its proper divisors (55531).

509491001 is a wasteful number, since it uses less digits than its factorization.

509491001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55530.

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 509491001 is about 22571.9073407632. The cubic root of 509491001 is about 798.6910892964.

The spelling of 509491001 in words is "five hundred nine million, four hundred ninety-one thousand, one".