1851557 has 2 divisors, whose sum is σ = 1851558. Its totient is φ = 1851556.

The previous prime is 1851547. The next prime is 1851559. The reversal of 1851557 is 7551581.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1331716 + 519841 = 1154^2 + 721^2 .

It is an emirp because it is prime and its reverse (7551581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1851557 - 2⁴ = 1851541 is a prime.

Together with 1851559, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1851559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 925778 + 925779.

It is an arithmetic number, because the mean of its divisors is an integer number (925779).

2^1851557 is an apocalyptic number.

It is an amenable number.

1851557 is a deficient number, since it is larger than the sum of its proper divisors (1).

1851557 is an equidigital number, since it uses as much as digits as its factorization.

1851557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7000, while the sum is 32.

The square root of 1851557 is about 1360.7192950789. The cubic root of 1851557 is about 122.7945321477.

The spelling of 1851557 in words is "one million, eight hundred fifty-one thousand, five hundred fifty-seven".