857721513 has 8 divisors (see below), whose sum is σ = 1247594976. Its totient is φ = 519831200.

The previous prime is 857721511. The next prime is 857721539. The reversal of 857721513 is 315127758.

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

It is a cyclic number.

It is not a de Polignac number, because 857721513 - 2¹ = 857721511 is a prime.

It is not an unprimeable number, because it can be changed into a prime (857721511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12995748 + ... + 12995813.

It is an arithmetic number, because the mean of its divisors is an integer number (155949372).

Almost surely, 2^857721513 is an apocalyptic number.

It is an amenable number.

857721513 is a deficient number, since it is larger than the sum of its proper divisors (389873463).

857721513 is a wasteful number, since it uses less digits than its factorization.

857721513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25991575.

The product of its digits is 58800, while the sum is 39.

The square root of 857721513 is about 29286.8829512463. The cubic root of 857721513 is about 950.1279654030.

The spelling of 857721513 in words is "eight hundred fifty-seven million, seven hundred twenty-one thousand, five hundred thirteen".