20690945 has 8 divisors (see below), whose sum is σ = 27086400. Its totient is φ = 15047920.

The previous prime is 20690939. The next prime is 20690977. The reversal of 20690945 is 54909602.

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

It is not a de Polignac number, because 20690945 - 2⁸ = 20690689 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 188045 + ... + 188154.

It is an arithmetic number, because the mean of its divisors is an integer number (3385800).

Almost surely, 2^20690945 is an apocalyptic number.

It is an amenable number.

20690945 is a deficient number, since it is larger than the sum of its proper divisors (6395455).

20690945 is a wasteful number, since it uses less digits than its factorization.

20690945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 376215.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 20690945 is about 4548.7300425503. The cubic root of 20690945 is about 274.5322959160.

The spelling of 20690945 in words is "twenty million, six hundred ninety thousand, nine hundred forty-five".