201005551 has 2 divisors, whose sum is σ = 201005552. Its totient is φ = 201005550.

The previous prime is 201005527. The next prime is 201005557. The reversal of 201005551 is 155500102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 201005551 - 2²³ = 192616943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201005557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100502775 + 100502776.

It is an arithmetic number, because the mean of its divisors is an integer number (100502776).

Almost surely, 2^201005551 is an apocalyptic number.

201005551 is a deficient number, since it is larger than the sum of its proper divisors (1).

201005551 is an equidigital number, since it uses as much as digits as its factorization.

201005551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 250, while the sum is 19.

The square root of 201005551 is about 14177.6426460819. The cubic root of 201005551 is about 585.7819926630.

Adding to 201005551 its reverse (155500102), we get a palindrome (356505653).

It can be divided in two parts, 20100 and 5551, that added together give a triangular number (25651 = T₂₂₆).

The spelling of 201005551 in words is "two hundred one million, five thousand, five hundred fifty-one".