20782917 has 12 divisors (see below), whose sum is σ = 30071340. Its totient is φ = 13831488.

The previous prime is 20782877. The next prime is 20782919. The reversal of 20782917 is 71928702.

It can be written as a sum of positive squares in 2 ways, for example, as 10246401 + 10536516 = 3201^2 + 3246^2 .

It is not a de Polignac number, because 20782917 - 2¹¹ = 20780869 is a prime.

It is a super-3 number, since 3×20782917³ (a number of 23 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20782919) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4753 + ... + 8009.

It is an arithmetic number, because the mean of its divisors is an integer number (2505945).

Almost surely, 2^20782917 is an apocalyptic number.

It is an amenable number.

20782917 is a deficient number, since it is larger than the sum of its proper divisors (9288423).

20782917 is a wasteful number, since it uses less digits than its factorization.

20782917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3972 (or 3969 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 20782917 is about 4558.8284679290. The cubic root of 20782917 is about 274.9384633660.

The spelling of 20782917 in words is "twenty million, seven hundred eighty-two thousand, nine hundred seventeen".