20675405 has 8 divisors (see below), whose sum is σ = 25666200. Its totient is φ = 15969856.

The previous prime is 20675399. The next prime is 20675423. The reversal of 20675405 is 50457602.

It can be written as a sum of positive squares in 4 ways, for example, as 196 + 20675209 = 14^2 + 4547^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 20675405 - 2¹⁴ = 20659021 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71150 + ... + 71439.

It is an arithmetic number, because the mean of its divisors is an integer number (3208275).

Almost surely, 2^20675405 is an apocalyptic number.

It is an amenable number.

20675405 is a deficient number, since it is larger than the sum of its proper divisors (4990795).

20675405 is a wasteful number, since it uses less digits than its factorization.

20675405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142623.

The product of its (nonzero) digits is 8400, while the sum is 29.

The square root of 20675405 is about 4547.0215526210. The cubic root of 20675405 is about 274.4635492512.

The spelling of 20675405 in words is "twenty million, six hundred seventy-five thousand, four hundred five".