1855649 has 2 divisors, whose sum is σ = 1855650. Its totient is φ = 1855648.

The previous prime is 1855627. The next prime is 1855687. The reversal of 1855649 is 9465581.

It is an a-pointer prime, because the next prime (1855687) can be obtained adding 1855649 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1690000 + 165649 = 1300^2 + 407^2 .

It is a cyclic number.

It is not a de Polignac number, because 1855649 - 2⁸ = 1855393 is a prime.

It is a super-2 number, since 2×1855649² = 6886866422402, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1855349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 927824 + 927825.

It is an arithmetic number, because the mean of its divisors is an integer number (927825).

2^1855649 is an apocalyptic number.

It is an amenable number.

1855649 is a deficient number, since it is larger than the sum of its proper divisors (1).

1855649 is an equidigital number, since it uses as much as digits as its factorization.

1855649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43200, while the sum is 38.

The square root of 1855649 is about 1362.2220817473. Note that the first 3 decimals coincide. The cubic root of 1855649 is about 122.8849255332.

The spelling of 1855649 in words is "one million, eight hundred fifty-five thousand, six hundred forty-nine".