20678405 has 8 divisors (see below), whose sum is σ = 27069984. Its totient is φ = 15038800.

The previous prime is 20678401. The next prime is 20678417. The reversal of 20678405 is 50487602.

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

It is not a de Polignac number, because 20678405 - 2² = 20678401 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 (20678401) 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, 187931 + ... + 188040.

It is an arithmetic number, because the mean of its divisors is an integer number (3383748).

Almost surely, 2^20678405 is an apocalyptic number.

It is an amenable number.

20678405 is a deficient number, since it is larger than the sum of its proper divisors (6391579).

20678405 is a wasteful number, since it uses less digits than its factorization.

20678405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 375987.

The product of its (nonzero) digits is 13440, while the sum is 32.

The square root of 20678405 is about 4547.3514269297. The cubic root of 20678405 is about 274.4768234906.

The spelling of 20678405 in words is "twenty million, six hundred seventy-eight thousand, four hundred five".