201023551 has 2 divisors, whose sum is σ = 201023552. Its totient is φ = 201023550.

The previous prime is 201023549. The next prime is 201023567. The reversal of 201023551 is 155320102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 201023551 - 2¹ = 201023549 is a prime.

Together with 201023549, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201053551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100511775 + 100511776.

It is an arithmetic number, because the mean of its divisors is an integer number (100511776).

Almost surely, 2^201023551 is an apocalyptic number.

201023551 is a deficient number, since it is larger than the sum of its proper divisors (1).

201023551 is an equidigital number, since it uses as much as digits as its factorization.

201023551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 201023551 is about 14178.2774341596. The cubic root of 201023551 is about 585.7994776879.

Adding to 201023551 its reverse (155320102), we get a palindrome (356343653).

It can be divided in two parts, 20102 and 3551, that added together give a triangular number (23653 = T₂₁₇).

The spelling of 201023551 in words is "two hundred one million, twenty-three thousand, five hundred fifty-one".