781349138 has 8 divisors (see below), whose sum is σ = 1240966332. Its totient is φ = 367693696.

The previous prime is 781349119. The next prime is 781349143. The reversal of 781349138 is 831943187.

It can be written as a sum of positive squares in 2 ways, for example, as 772450849 + 8898289 = 27793^2 + 2983^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×781349138² = 1221012950906686088, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11490395 + ... + 11490462.

Almost surely, 2^781349138 is an apocalyptic number.

781349138 is a deficient number, since it is larger than the sum of its proper divisors (459617194).

781349138 is a wasteful number, since it uses less digits than its factorization.

781349138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22980876.

The product of its digits is 145152, while the sum is 44.

The square root of 781349138 is about 27952.6230969474. The cubic root of 781349138 is about 921.0468306139.

The spelling of 781349138 in words is "seven hundred eighty-one million, three hundred forty-nine thousand, one hundred thirty-eight".