20687049 has 8 divisors (see below), whose sum is σ = 30647520. Its totient is φ = 13791348.

The previous prime is 20687047. The next prime is 20687077. The reversal of 20687049 is 94078602.

It is not a de Polignac number, because 20687049 - 2¹ = 20687047 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20687047) 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 7 ways as a sum of consecutive naturals, for example, 383067 + ... + 383120.

It is an arithmetic number, because the mean of its divisors is an integer number (3830940).

Almost surely, 2^20687049 is an apocalyptic number.

It is an amenable number.

20687049 is a deficient number, since it is larger than the sum of its proper divisors (9960471).

20687049 is an equidigital number, since it uses as much as digits as its factorization.

20687049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 766196 (or 766190 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 20687049 is about 4548.3017709910. The cubic root of 20687049 is about 274.5150638214.

The spelling of 20687049 in words is "twenty million, six hundred eighty-seven thousand, forty-nine".