509686994 has 4 divisors (see below), whose sum is σ = 764530494. Its totient is φ = 254843496.

The previous prime is 509686993. The next prime is 509686999. The reversal of 509686994 is 499686905.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 499686905 = 5 ⋅99937381.

It can be written as a sum of positive squares in only one way, i.e., 363397969 + 146289025 = 19063^2 + 12095^2 .

It is not an unprimeable number, because it can be changed into a prime (509686993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127421747 + ... + 127421750.

Almost surely, 2^509686994 is an apocalyptic number.

509686994 is a deficient number, since it is larger than the sum of its proper divisors (254843500).

509686994 is a wasteful number, since it uses less digits than its factorization.

509686994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254843499.

The product of its (nonzero) digits is 4199040, while the sum is 56.

The square root of 509686994 is about 22576.2484483140. The cubic root of 509686994 is about 798.7934907089.

The spelling of 509686994 in words is "five hundred nine million, six hundred eighty-six thousand, nine hundred ninety-four".