20909313 has 16 divisors (see below), whose sum is σ = 31637760. Its totient is φ = 13642128.

The previous prime is 20909311. The next prime is 20909321. The reversal of 20909313 is 31390902.

It is not a de Polignac number, because 20909313 - 2¹ = 20909311 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20909311) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 6970 + ... + 9507.

It is an arithmetic number, because the mean of its divisors is an integer number (1977360).

Almost surely, 2^20909313 is an apocalyptic number.

It is an amenable number.

20909313 is a deficient number, since it is larger than the sum of its proper divisors (10728447).

20909313 is a wasteful number, since it uses less digits than its factorization.

20909313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16533 (or 16527 counting only the distinct ones).

The product of its (nonzero) digits is 1458, while the sum is 27.

The square root of 20909313 is about 4572.6702264651. The cubic root of 20909313 is about 275.4947040219.

The spelling of 20909313 in words is "twenty million, nine hundred nine thousand, three hundred thirteen".