20859669 has 6 divisors (see below), whose sum is σ = 30130646. Its totient is φ = 13906440.

The previous prime is 20859667. The next prime is 20859679. The reversal of 20859669 is 96695802.

It can be written as a sum of positive squares in only one way, i.e., 17388900 + 3470769 = 4170^2 + 1863^2 .

It is not a de Polignac number, because 20859669 - 2¹ = 20859667 is a prime.

It is a super-2 number, since 2×20859669² = 870251581579122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20859661) 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 5 ways as a sum of consecutive naturals, for example, 1158862 + ... + 1158879.

Almost surely, 2^20859669 is an apocalyptic number.

It is an amenable number.

20859669 is a deficient number, since it is larger than the sum of its proper divisors (9270977).

20859669 is a wasteful number, since it uses less digits than its factorization.

20859669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2317747 (or 2317744 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The square root of 20859669 is about 4567.2386624743. The cubic root of 20859669 is about 275.2764998604.

It can be divided in two parts, 20859 and 669, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 20859669 in words is "twenty million, eight hundred fifty-nine thousand, six hundred sixty-nine".