20406853 has 4 divisors (see below), whose sum is σ = 20509600. Its totient is φ = 20304108.

The previous prime is 20406833. The next prime is 20406917. The reversal of 20406853 is 35860402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 35860402 = 2 ⋅17930201.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20406853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20406803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51075 + ... + 51472.

It is an arithmetic number, because the mean of its divisors is an integer number (5127400).

Almost surely, 2^20406853 is an apocalyptic number.

It is an amenable number.

20406853 is a deficient number, since it is larger than the sum of its proper divisors (102747).

20406853 is a wasteful number, since it uses less digits than its factorization.

20406853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102746.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 20406853 is about 4517.3944924038. The cubic root of 20406853 is about 273.2700347509.

The spelling of 20406853 in words is "twenty million, four hundred six thousand, eight hundred fifty-three".