86857421 has 4 divisors (see below), whose sum is σ = 99265632. Its totient is φ = 74449212.

The previous prime is 86857399. The next prime is 86857427. The reversal of 86857421 is 12475868.

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 a cyclic number.

It is not a de Polignac number, because 86857421 - 2²⁶ = 19748557 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 (86857427) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6204095 + ... + 6204108.

It is an arithmetic number, because the mean of its divisors is an integer number (24816408).

Almost surely, 2^86857421 is an apocalyptic number.

It is an amenable number.

86857421 is a deficient number, since it is larger than the sum of its proper divisors (12408211).

86857421 is a wasteful number, since it uses less digits than its factorization.

86857421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12408210.

The product of its digits is 107520, while the sum is 41.

The square root of 86857421 is about 9319.7328824382. The cubic root of 86857421 is about 442.8625706832.

It can be divided in two parts, 86857 and 421, that added together give a palindrome (87278).

The spelling of 86857421 in words is "eighty-six million, eight hundred fifty-seven thousand, four hundred twenty-one".