681850915 has 4 divisors (see below), whose sum is σ = 818221104. Its totient is φ = 545480728.

The previous prime is 681850903. The next prime is 681850933. The reversal of 681850915 is 519058186.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 519058186 = 2 ⋅259529093.

It is a cyclic number.

It is not a de Polignac number, because 681850915 - 2¹³ = 681842723 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68185087 + ... + 68185096.

It is an arithmetic number, because the mean of its divisors is an integer number (204555276).

Almost surely, 2^681850915 is an apocalyptic number.

681850915 is a deficient number, since it is larger than the sum of its proper divisors (136370189).

681850915 is a wasteful number, since it uses less digits than its factorization.

681850915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136370188.

The product of its (nonzero) digits is 86400, while the sum is 43.

The square root of 681850915 is about 26112.2751785439. The cubic root of 681850915 is about 880.1630702449.

The spelling of 681850915 in words is "six hundred eighty-one million, eight hundred fifty thousand, nine hundred fifteen".