20533554551 has 4 divisors (see below), whose sum is σ = 20536291512. Its totient is φ = 20530817592.

The previous prime is 20533554541. The next prime is 20533554557. The reversal of 20533554551 is 15545533502.

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

It is a cyclic number.

It is not a de Polignac number, because 20533554551 - 2¹⁸ = 20533292407 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 (20533554557) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1357196 + ... + 1372241.

It is an arithmetic number, because the mean of its divisors is an integer number (5134072878).

Almost surely, 2^20533554551 is an apocalyptic number.

20533554551 is a deficient number, since it is larger than the sum of its proper divisors (2736961).

20533554551 is an equidigital number, since it uses as much as digits as its factorization.

20533554551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2736960.

The product of its (nonzero) digits is 225000, while the sum is 38.

The spelling of 20533554551 in words is "twenty billion, five hundred thirty-three million, five hundred fifty-four thousand, five hundred fifty-one".