1801381 has 4 divisors (see below), whose sum is σ = 1815264. Its totient is φ = 1787500.

The previous prime is 1801363. The next prime is 1801403. The reversal of 1801381 is 1831081.

1801381 = 46² + 47² + ... + 176².

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 1801381 - 2¹⁹ = 1277093 is a prime.

It is a super-2 number, since 2×1801381² = 6489947014322, which contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1801361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6745 + ... + 7006.

It is an arithmetic number, because the mean of its divisors is an integer number (453816).

2^1801381 is an apocalyptic number.

It is an amenable number.

1801381 is a deficient number, since it is larger than the sum of its proper divisors (13883).

1801381 is a wasteful number, since it uses less digits than its factorization.

1801381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13882.

The product of its (nonzero) digits is 192, while the sum is 22.

The square root of 1801381 is about 1342.1553561343. The cubic root of 1801381 is about 121.6751412958.

The spelling of 1801381 in words is "one million, eight hundred one thousand, three hundred eighty-one".