20690404 has 48 divisors (see below), whose sum is σ = 43182720. Its totient is φ = 8490240.

The previous prime is 20690393. The next prime is 20690429. The reversal of 20690404 is 40409602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76782 + ... + 77050.

It is an arithmetic number, because the mean of its divisors is an integer number (899640).

Almost surely, 2^20690404 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20690404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21591360).

20690404 is an abundant number, since it is smaller than the sum of its proper divisors (22492316).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20690404 is a wasteful number, since it uses less digits than its factorization.

20690404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388 (or 386 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 20690404 is about 4548.6705750142. The cubic root of 20690404 is about 274.5299031903.

The spelling of 20690404 in words is "twenty million, six hundred ninety thousand, four hundred four".