781313 has 4 divisors (see below), whose sum is σ = 841428. Its totient is φ = 721200.

The previous prime is 781309. The next prime is 781321. The reversal of 781313 is 313187.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 313187 = 7 ⋅44741.

It can be written as a sum of positive squares in 2 ways, for example, as 238144 + 543169 = 488^2 + 737^2 .

It is a cyclic number.

It is not a de Polignac number, because 781313 - 2² = 781309 is a prime.

It is a super-2 number, since 2×781313² = 1220900007938, which contains 22 as substring.

It is a Duffinian number.

781313 is a modest number, since divided by 1313 gives 78 as remainder.

It is not an unprimeable number, because it can be changed into a prime (781513) 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, 30038 + ... + 30063.

It is an arithmetic number, because the mean of its divisors is an integer number (210357).

It is a Proth number, since it is equal to 763 ⋅ 2¹⁰ + 1 and 763 < 2¹⁰.

2⁷⁸¹³¹³ is an apocalyptic number.

It is an amenable number.

781313 is a deficient number, since it is larger than the sum of its proper divisors (60115).

781313 is a wasteful number, since it uses less digits than its factorization.

781313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60114.

The product of its digits is 504, while the sum is 23.

The square root of 781313 is about 883.9191139465. The cubic root of 781313 is about 92.1032630686.

The spelling of 781313 in words is "seven hundred eighty-one thousand, three hundred thirteen".