20500553551 has 2 divisors, whose sum is σ = 20500553552. Its totient is φ = 20500553550.

The previous prime is 20500553539. The next prime is 20500553581. The reversal of 20500553551 is 15535500502.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20500553551 - 2¹⁵ = 20500520783 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20500553581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10250276775 + 10250276776.

It is an arithmetic number, because the mean of its divisors is an integer number (10250276776).

Almost surely, 2^20500553551 is an apocalyptic number.

20500553551 is a deficient number, since it is larger than the sum of its proper divisors (1).

20500553551 is an equidigital number, since it uses as much as digits as its factorization.

20500553551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18750, while the sum is 31.

The spelling of 20500553551 in words is "twenty billion, five hundred million, five hundred fifty-three thousand, five hundred fifty-one".