20135405 has 8 divisors (see below), whose sum is σ = 24219000. Its totient is φ = 16070656.

The previous prime is 20135377. The next prime is 20135431. The reversal of 20135405 is 50453102.

It can be written as a sum of positive squares in 4 ways, for example, as 2937796 + 17197609 = 1714^2 + 4147^2 .

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 20135405 - 2⁶ = 20135341 is a prime.

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, 2240 + ... + 6729.

It is an arithmetic number, because the mean of its divisors is an integer number (3027375).

Almost surely, 2^20135405 is an apocalyptic number.

It is an amenable number.

20135405 is a deficient number, since it is larger than the sum of its proper divisors (4083595).

20135405 is an equidigital number, since it uses as much as digits as its factorization.

20135405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9423.

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 20135405 is about 4487.2491573346. The cubic root of 20135405 is about 272.0529606001.

Adding to 20135405 its reverse (50453102), we get a palindrome (70588507).

The spelling of 20135405 in words is "twenty million, one hundred thirty-five thousand, four hundred five".