20001558 has 8 divisors (see below), whose sum is σ = 40003128. Its totient is φ = 6667184.

The previous prime is 20001557. The next prime is 20001613. The reversal of 20001558 is 85510002.

It is a sphenic number, since it is the product of 3 distinct primes.

20001558 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1666791 + ... + 1666802.

It is an arithmetic number, because the mean of its divisors is an integer number (5000391).

Almost surely, 2^20001558 is an apocalyptic number.

20001558 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20001558 is a wasteful number, since it uses less digits than its factorization.

20001558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3333598.

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 20001558 is about 4472.3101413028. The cubic root of 20001558 is about 271.4488099142.

The spelling of 20001558 in words is "twenty million, one thousand, five hundred fifty-eight".