21280086 has 24 divisors (see below), whose sum is σ = 46229040. Its totient is φ = 7074576.

The previous prime is 21280081. The next prime is 21280093. The reversal of 21280086 is 68008212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21280081) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6556 + ... + 9248.

It is an arithmetic number, because the mean of its divisors is an integer number (1926210).

Almost surely, 2^21280086 is an apocalyptic number.

21280086 is an abundant number, since it is smaller than the sum of its proper divisors (24948954).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21280086 is a wasteful number, since it uses less digits than its factorization.

21280086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3140 (or 3137 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 21280086 is about 4613.0343592911. The cubic root of 21280086 is about 277.1135697508.

Adding to 21280086 its reverse (68008212), we get a palindrome (89288298).

The spelling of 21280086 in words is "twenty-one million, two hundred eighty thousand, eighty-six".