20421354 has 8 divisors (see below), whose sum is σ = 40842720. Its totient is φ = 6807116.

The previous prime is 20421347. The next prime is 20421367. The reversal of 20421354 is 45312402.

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

20421354 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 20421354.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1701774 + ... + 1701785.

It is an arithmetic number, because the mean of its divisors is an integer number (5105340).

Almost surely, 2^20421354 is an apocalyptic number.

20421354 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.

20421354 is a wasteful number, since it uses less digits than its factorization.

20421354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3403564.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 20421354 is about 4518.9992254923. Note that the first 3 decimals coincide. The cubic root of 20421354 is about 273.3347474975.

Adding to 20421354 its reverse (45312402), we get a palindrome (65733756).

The spelling of 20421354 in words is "twenty million, four hundred twenty-one thousand, three hundred fifty-four".