20860405 has 8 divisors (see below), whose sum is σ = 25163352. Its totient is φ = 16601088.

The previous prime is 20860403. The next prime is 20860409. The reversal of 20860405 is 50406802.

It can be written as a sum of positive squares in 4 ways, for example, as 2916 + 20857489 = 54^2 + 4567^2 .

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

It is not a de Polignac number, because 20860405 - 2¹ = 20860403 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20860405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20860403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9844 + ... + 11773.

It is an arithmetic number, because the mean of its divisors is an integer number (3145419).

Almost surely, 2^20860405 is an apocalyptic number.

It is an amenable number.

20860405 is a deficient number, since it is larger than the sum of its proper divisors (4302947).

20860405 is a wasteful number, since it uses less digits than its factorization.

20860405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21815.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 20860405 is about 4567.3192356129. The cubic root of 20860405 is about 275.2797373857.

The spelling of 20860405 in words is "twenty million, eight hundred sixty thousand, four hundred five".