781281113 has 4 divisors (see below), whose sum is σ = 791983668. Its totient is φ = 770578560.

The previous prime is 781281101. The next prime is 781281139. The reversal of 781281113 is 311182187.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 311182187 = 8537 ⋅36451.

It can be written as a sum of positive squares in 2 ways, for example, as 185286544 + 595994569 = 13612^2 + 24413^2 .

It is a cyclic number.

It is not a de Polignac number, because 781281113 - 2¹⁶ = 781215577 is a prime.

It is a super-2 number, since 2×781281113² = 1220800355061037538, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 781281113.

It is not an unprimeable number, because it can be changed into a prime (781281713) 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, 5351168 + ... + 5351313.

It is an arithmetic number, because the mean of its divisors is an integer number (197995917).

Almost surely, 2^781281113 is an apocalyptic number.

781281113 is a gapful number since it is divisible by the number (73) formed by its first and last digit.

It is an amenable number.

781281113 is a deficient number, since it is larger than the sum of its proper divisors (10702555).

781281113 is a wasteful number, since it uses less digits than its factorization.

781281113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10702554.

The product of its digits is 2688, while the sum is 32.

The square root of 781281113 is about 27951.4062794701. The cubic root of 781281113 is about 921.0201007668.

The spelling of 781281113 in words is "seven hundred eighty-one million, two hundred eighty-one thousand, one hundred thirteen".