20434821 has 32 divisors (see below), whose sum is σ = 31173120. Its totient is φ = 11793600.

The previous prime is 20434811. The next prime is 20434853. The reversal of 20434821 is 12843402.

It is not a de Polignac number, because 20434821 - 2⁵ = 20434789 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20434791 and 20434800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20434811) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 125286 + ... + 125448.

It is an arithmetic number, because the mean of its divisors is an integer number (974160).

Almost surely, 2^20434821 is an apocalyptic number.

It is an amenable number.

20434821 is a deficient number, since it is larger than the sum of its proper divisors (10738299).

20434821 is a wasteful number, since it uses less digits than its factorization.

20434821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337.

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 20434821 is about 4520.4890222187. The cubic root of 20434821 is about 273.3948184439.

The spelling of 20434821 in words is "twenty million, four hundred thirty-four thousand, eight hundred twenty-one".