20909417 has 8 divisors (see below), whose sum is σ = 21275016. Its totient is φ = 20547072.

The previous prime is 20909389. The next prime is 20909419. The reversal of 20909417 is 71490902.

It can be written as a sum of positive squares in 4 ways, for example, as 6651241 + 14258176 = 2579^2 + 3776^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 20909417 - 2¹⁶ = 20843881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20909419) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14543 + ... + 15915.

It is an arithmetic number, because the mean of its divisors is an integer number (2659377).

Almost surely, 2^20909417 is an apocalyptic number.

It is an amenable number.

20909417 is a deficient number, since it is larger than the sum of its proper divisors (365599).

20909417 is a wasteful number, since it uses less digits than its factorization.

20909417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1627.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 20909417 is about 4572.6815983622. The cubic root of 20909417 is about 275.4951607785.

The spelling of 20909417 in words is "twenty million, nine hundred nine thousand, four hundred seventeen".