20905418 has 8 divisors (see below), whose sum is σ = 31413312. Its totient is φ = 10434316.

The previous prime is 20905403. The next prime is 20905429. The reversal of 20905418 is 81450902.

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

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 3 ways as a sum of consecutive naturals, for example, 7730 + ... + 10077.

It is an arithmetic number, because the mean of its divisors is an integer number (3926664).

Almost surely, 2^20905418 is an apocalyptic number.

20905418 is a deficient number, since it is larger than the sum of its proper divisors (10507894).

20905418 is a wasteful number, since it uses less digits than its factorization.

20905418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18396.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 20905418 is about 4572.2443066835. The cubic root of 20905418 is about 275.4775965173.

It can be divided in two parts, 20905 and 418, that multiplied together give a triangular number (8738290 = T₄₁₈₀).

The spelling of 20905418 in words is "twenty million, nine hundred five thousand, four hundred eighteen".