1851261 has 4 divisors (see below), whose sum is σ = 2468352. Its totient is φ = 1234172.

The previous prime is 1851259. The next prime is 1851271. The reversal of 1851261 is 1621581.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1851261 - 2¹ = 1851259 is a prime.

It is an Ulam number.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1851271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 308541 + ... + 308546.

It is an arithmetic number, because the mean of its divisors is an integer number (617088).

2^1851261 is an apocalyptic number.

It is an amenable number.

1851261 is a deficient number, since it is larger than the sum of its proper divisors (617091).

1851261 is an equidigital number, since it uses as much as digits as its factorization.

1851261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 617090.

The product of its digits is 480, while the sum is 24.

The square root of 1851261 is about 1360.6105247278. The cubic root of 1851261 is about 122.7879882644.

It can be divided in two parts, 1851 and 261, that added together give a palindrome (2112).

The spelling of 1851261 in words is "one million, eight hundred fifty-one thousand, two hundred sixty-one".