20694639 has 32 divisors (see below), whose sum is σ = 33030144. Its totient is φ = 11276640.

The previous prime is 20694637. The next prime is 20694647. The reversal of 20694639 is 93649602.

20694639 = 802² + 803² + ... + 832².

It is a happy number.

It is not a de Polignac number, because 20694639 - 2¹ = 20694637 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 20694597 and 20694606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20694637) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 53842 + ... + 54224.

It is an arithmetic number, because the mean of its divisors is an integer number (1032192).

Almost surely, 2^20694639 is an apocalyptic number.

20694639 is a deficient number, since it is larger than the sum of its proper divisors (12335505).

20694639 is a wasteful number, since it uses less digits than its factorization.

20694639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 507.

The product of its (nonzero) digits is 69984, while the sum is 39.

The square root of 20694639 is about 4549.1360718273. The cubic root of 20694639 is about 274.5486325624.

The spelling of 20694639 in words is "twenty million, six hundred ninety-four thousand, six hundred thirty-nine".