20212405 has 16 divisors (see below), whose sum is σ = 25789104. Its totient is φ = 15155200.

The previous prime is 20212399. The next prime is 20212417. The reversal of 20212405 is 50421202.

It can be written as a sum of positive squares in 8 ways, for example, as 4268356 + 15944049 = 2066^2 + 3993^2 .

It is not a de Polignac number, because 20212405 - 2⁵ = 20212373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33789 + ... + 34381.

It is an arithmetic number, because the mean of its divisors is an integer number (1611819).

Almost surely, 2^20212405 is an apocalyptic number.

It is an amenable number.

20212405 is a deficient number, since it is larger than the sum of its proper divisors (5576699).

20212405 is a wasteful number, since it uses less digits than its factorization.

20212405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1016.

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 20212405 is about 4495.8208371776. The cubic root of 20212405 is about 272.3993062860.

Adding to 20212405 its reverse (50421202), we get a palindrome (70633607).

The spelling of 20212405 in words is "twenty million, two hundred twelve thousand, four hundred five".