20925917 has 4 divisors (see below), whose sum is σ = 21090816. Its totient is φ = 20761020.

The previous prime is 20925913. The next prime is 20925923. The reversal of 20925917 is 71952902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20925917 - 2² = 20925913 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20925911) by changing a digit.

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, 82259 + ... + 82512.

It is an arithmetic number, because the mean of its divisors is an integer number (5272704).

Almost surely, 2^20925917 is an apocalyptic number.

It is an amenable number.

20925917 is a deficient number, since it is larger than the sum of its proper divisors (164899).

20925917 is a wasteful number, since it uses less digits than its factorization.

20925917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164898.

The product of its (nonzero) digits is 11340, while the sum is 35.

The square root of 20925917 is about 4574.4854355435. The cubic root of 20925917 is about 275.5676078006.

The spelling of 20925917 in words is "twenty million, nine hundred twenty-five thousand, nine hundred seventeen".