509969381 has 2 divisors, whose sum is σ = 509969382. Its totient is φ = 509969380.

The previous prime is 509969371. The next prime is 509969399. The reversal of 509969381 is 183969905.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 508908481 + 1060900 = 22559^2 + 1030^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-509969381 is a prime.

It is a super-2 number, since 2×509969381² = 520137539115046322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (509969351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 254984690 + 254984691.

It is an arithmetic number, because the mean of its divisors is an integer number (254984691).

Almost surely, 2^509969381 is an apocalyptic number.

It is an amenable number.

509969381 is a deficient number, since it is larger than the sum of its proper divisors (1).

509969381 is an equidigital number, since it uses as much as digits as its factorization.

509969381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 524880, while the sum is 50.

The square root of 509969381 is about 22582.5016550426. The cubic root of 509969381 is about 798.9409846642.

The spelling of 509969381 in words is "five hundred nine million, nine hundred sixty-nine thousand, three hundred eighty-one".