1800551 has 2 divisors, whose sum is σ = 1800552. Its totient is φ = 1800550.

The previous prime is 1800541. The next prime is 1800553. The reversal of 1800551 is 1550081.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1800551 - 2¹⁰ = 1799527 is a prime.

Together with 1800553, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1800553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 900275 + 900276.

It is an arithmetic number, because the mean of its divisors is an integer number (900276).

2^1800551 is an apocalyptic number.

1800551 is a deficient number, since it is larger than the sum of its proper divisors (1).

1800551 is an equidigital number, since it uses as much as digits as its factorization.

1800551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 200, while the sum is 20.

The square root of 1800551 is about 1341.8461163636. The cubic root of 1800551 is about 121.6564508426.

The spelling of 1800551 in words is "one million, eight hundred thousand, five hundred fifty-one".