20687605 has 8 divisors (see below), whose sum is σ = 25104600. Its totient is φ = 16363776.

The previous prime is 20687593. The next prime is 20687617. The reversal of 20687605 is 50678602.

It is an interprime number because it is at equal distance from previous prime (20687593) and next prime (20687617).

It can be written as a sum of positive squares in 4 ways, for example, as 239121 + 20448484 = 489^2 + 4522^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20687605 - 2⁵ = 20687573 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22800 + ... + 23689.

It is an arithmetic number, because the mean of its divisors is an integer number (3138075).

Almost surely, 2^20687605 is an apocalyptic number.

It is an amenable number.

20687605 is a deficient number, since it is larger than the sum of its proper divisors (4416995).

20687605 is an equidigital number, since it uses as much as digits as its factorization.

20687605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46583.

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 20687605 is about 4548.3628922943. The cubic root of 20687605 is about 274.5175231541.

The spelling of 20687605 in words is "twenty million, six hundred eighty-seven thousand, six hundred five".