20401284 has 12 divisors (see below), whose sum is σ = 47603024. Its totient is φ = 6800424.

The previous prime is 20401273. The next prime is 20401291. The reversal of 20401284 is 48210402.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 20401284.

It is an unprimeable number.

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, 850042 + ... + 850065.

Almost surely, 2^20401284 is an apocalyptic number.

It is an amenable number.

20401284 is an abundant number, since it is smaller than the sum of its proper divisors (27201740).

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

20401284 is a wasteful number, since it uses less digits than its factorization.

20401284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1700114 (or 1700112 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

The square root of 20401284 is about 4516.7780552071. The cubic root of 20401284 is about 273.2451741598.

Adding to 20401284 its reverse (48210402), we get a palindrome (68611686).

The spelling of 20401284 in words is "twenty million, four hundred one thousand, two hundred eighty-four".