85621521 has 4 divisors (see below), whose sum is σ = 114162032. Its totient is φ = 57081012.

The previous prime is 85621517. The next prime is 85621559. The reversal of 85621521 is 12512658.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 85621521 - 2² = 85621517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85621561) by changing a digit.

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, 14270251 + ... + 14270256.

It is an arithmetic number, because the mean of its divisors is an integer number (28540508).

Almost surely, 2^85621521 is an apocalyptic number.

It is an amenable number.

85621521 is a deficient number, since it is larger than the sum of its proper divisors (28540511).

85621521 is a wasteful number, since it uses less digits than its factorization.

85621521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28540510.

The product of its digits is 4800, while the sum is 30.

The square root of 85621521 is about 9253.1897743427. The cubic root of 85621521 is about 440.7520214649.

The spelling of 85621521 in words is "eighty-five million, six hundred twenty-one thousand, five hundred twenty-one".