1901005 has 4 divisors (see below), whose sum is σ = 2281212. Its totient is φ = 1520800.

The previous prime is 1900981. The next prime is 1901021. The reversal of 1901005 is 5001091.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5001091 = 1619 ⋅3089.

It can be written as a sum of positive squares in 2 ways, for example, as 522729 + 1378276 = 723^2 + 1174^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1901005 is a prime.

It is a super-2 number, since 2×1901005² = 7227640020050, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1901005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 190096 + ... + 190105.

It is an arithmetic number, because the mean of its divisors is an integer number (570303).

2^1901005 is an apocalyptic number.

It is an amenable number.

1901005 is a deficient number, since it is larger than the sum of its proper divisors (380207).

1901005 is an equidigital number, since it uses as much as digits as its factorization.

1901005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 380206.

The product of its (nonzero) digits is 45, while the sum is 16.

The square root of 1901005 is about 1378.7693788303. The cubic root of 1901005 is about 123.8780669233.

Adding to 1901005 its reverse (5001091), we get a palindrome (6902096).

The spelling of 1901005 in words is "one million, nine hundred one thousand, five".