20690390 has 32 divisors (see below), whose sum is σ = 43156800. Its totient is φ = 6994944.

The previous prime is 20690357. The next prime is 20690393. The reversal of 20690390 is 9309602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20690393) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3086 + ... + 7134.

It is an arithmetic number, because the mean of its divisors is an integer number (1348650).

Almost surely, 2^20690390 is an apocalyptic number.

20690390 is an abundant number, since it is smaller than the sum of its proper divisors (22466410).

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

20690390 is a wasteful number, since it uses less digits than its factorization.

20690390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4136.

The product of its (nonzero) digits is 2916, while the sum is 29.

The square root of 20690390 is about 4548.6690361028. The cubic root of 20690390 is about 274.5298412708.

Adding to 20690390 its reverse (9309602), we get a palindrome (29999992).

The spelling of 20690390 in words is "twenty million, six hundred ninety thousand, three hundred ninety".