20783917 has 16 divisors (see below), whose sum is σ = 26468352. Its totient is φ = 15847920.

The previous prime is 20783887. The next prime is 20783941. The reversal of 20783917 is 71938702.

It is not a de Polignac number, because 20783917 - 2¹⁵ = 20751149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20783957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 748 + ... + 6490.

It is an arithmetic number, because the mean of its divisors is an integer number (1654272).

Almost surely, 2^20783917 is an apocalyptic number.

It is an amenable number.

20783917 is a deficient number, since it is larger than the sum of its proper divisors (5684435).

20783917 is a wasteful number, since it uses less digits than its factorization.

20783917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5808.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 20783917 is about 4558.9381439103. The cubic root of 20783917 is about 274.9428729820.

It can be divided in two parts, 2078 and 3917, that added together give a palindrome (5995).

The spelling of 20783917 in words is "twenty million, seven hundred eighty-three thousand, nine hundred seventeen".