20953405 has 8 divisors (see below), whose sum is σ = 27429984. Its totient is φ = 15238800.

The previous prime is 20953381. The next prime is 20953411. The reversal of 20953405 is 50435902.

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

It is not a de Polignac number, because 20953405 - 2¹⁹ = 20429117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 190431 + ... + 190540.

It is an arithmetic number, because the mean of its divisors is an integer number (3428748).

Almost surely, 2^20953405 is an apocalyptic number.

It is an amenable number.

20953405 is a deficient number, since it is larger than the sum of its proper divisors (6476579).

20953405 is a wasteful number, since it uses less digits than its factorization.

20953405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380987.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 20953405 is about 4577.4889404563. The cubic root of 20953405 is about 275.6882156272.

The spelling of 20953405 in words is "twenty million, nine hundred fifty-three thousand, four hundred five".