20686458 has 32 divisors (see below), whose sum is σ = 44968896. Its totient is φ = 6306048.

The previous prime is 20686447. The next prime is 20686513. The reversal of 20686458 is 85468602.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7641 + ... + 9987.

It is an arithmetic number, because the mean of its divisors is an integer number (1405278).

Almost surely, 2^20686458 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20686458, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22484448).

20686458 is an abundant number, since it is smaller than the sum of its proper divisors (24282438).

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

20686458 is a wasteful number, since it uses less digits than its factorization.

20686458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2478.

The product of its (nonzero) digits is 92160, while the sum is 39.

The square root of 20686458 is about 4548.2368012231. The cubic root of 20686458 is about 274.5124496263.

The spelling of 20686458 in words is "twenty million, six hundred eighty-six thousand, four hundred fifty-eight".