85517021 has 8 divisors (see below), whose sum is σ = 92756664. Its totient is φ = 78522880.

The previous prime is 85517009. The next prime is 85517023. The reversal of 85517021 is 12071558.

It can be written as a sum of positive squares in 4 ways, for example, as 784996 + 84732025 = 886^2 + 9205^2 .

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 85517021 - 2²⁶ = 18408157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85517023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60650 + ... + 62043.

It is an arithmetic number, because the mean of its divisors is an integer number (11594583).

Almost surely, 2^85517021 is an apocalyptic number.

It is an amenable number.

85517021 is a deficient number, since it is larger than the sum of its proper divisors (7239643).

85517021 is a wasteful number, since it uses less digits than its factorization.

85517021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122751.

The product of its (nonzero) digits is 2800, while the sum is 29.

The square root of 85517021 is about 9247.5413489208. The cubic root of 85517021 is about 440.5726376823.

Adding to 85517021 its reverse (12071558), we get a palindrome (97588579).

The spelling of 85517021 in words is "eighty-five million, five hundred seventeen thousand, twenty-one".