85721515 has 8 divisors (see below), whose sum is σ = 112217328. Its totient is φ = 62342880.

The previous prime is 85721501. The next prime is 85721527. The reversal of 85721515 is 51512758.

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

It is not a de Polignac number, because 85721515 - 2¹¹ = 85719467 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 7 ways as a sum of consecutive naturals, for example, 779232 + ... + 779341.

It is an arithmetic number, because the mean of its divisors is an integer number (14027166).

Almost surely, 2^85721515 is an apocalyptic number.

85721515 is a deficient number, since it is larger than the sum of its proper divisors (26495813).

85721515 is a wasteful number, since it uses less digits than its factorization.

85721515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1558589.

The product of its digits is 14000, while the sum is 34.

The square root of 85721515 is about 9258.5914155448. The cubic root of 85721515 is about 440.9235336866.

The spelling of 85721515 in words is "eighty-five million, seven hundred twenty-one thousand, five hundred fifteen".