20531255551 has 8 divisors (see below), whose sum is σ = 20906539344. Its totient is φ = 20159368320.

The previous prime is 20531255533. The next prime is 20531255557. The reversal of 20531255551 is 15555213502.

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 20531255551 - 2¹¹ = 20531253503 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20531255557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 836940 + ... + 861121.

It is an arithmetic number, because the mean of its divisors is an integer number (2613317418).

Almost surely, 2^20531255551 is an apocalyptic number.

20531255551 is a deficient number, since it is larger than the sum of its proper divisors (375283793).

20531255551 is a wasteful number, since it uses less digits than its factorization.

20531255551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1698281.

The product of its (nonzero) digits is 37500, while the sum is 34.

The spelling of 20531255551 in words is "twenty billion, five hundred thirty-one million, two hundred fifty-five thousand, five hundred fifty-one".