20671550551 has 4 divisors (see below), whose sum is σ = 20676463704. Its totient is φ = 20666637400.

The previous prime is 20671550507. The next prime is 20671550561. The reversal of 20671550551 is 15505517602.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20671550551 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20671550551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20671550561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2450260 + ... + 2458681.

It is an arithmetic number, because the mean of its divisors is an integer number (5169115926).

Almost surely, 2^20671550551 is an apocalyptic number.

20671550551 is a deficient number, since it is larger than the sum of its proper divisors (4913153).

20671550551 is an equidigital number, since it uses as much as digits as its factorization.

20671550551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4913152.

The product of its (nonzero) digits is 52500, while the sum is 37.

The spelling of 20671550551 in words is "twenty billion, six hundred seventy-one million, five hundred fifty thousand, five hundred fifty-one".