1900001 has 4 divisors (see below), whose sum is σ = 1907652. Its totient is φ = 1892352.

The previous prime is 1899983. The next prime is 1900009. The reversal of 1900001 is 1000091.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1000091 = 31 ⋅32261.

It can be written as a sum of positive squares in 2 ways, for example, as 1221025 + 678976 = 1105^2 + 824^2 .

It is a cyclic number.

It is not a de Polignac number, because 1900001 - 2¹⁰ = 1898977 is a prime.

It is a super-2 number, since 2×1900001² = 7220007600002, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (1900009) 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, 3440 + ... + 3953.

It is an arithmetic number, because the mean of its divisors is an integer number (476913).

2^1900001 is an apocalyptic number.

It is an amenable number.

1900001 is a deficient number, since it is larger than the sum of its proper divisors (7651).

1900001 is an equidigital number, since it uses as much as digits as its factorization.

1900001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7650.

The product of its (nonzero) digits is 9, while the sum is 11.

The square root of 1900001 is about 1378.4052379471. The cubic root of 1900001 is about 123.8562546922.

Adding to 1900001 its reverse (1000091), we get a palindrome (2900092).

The spelling of 1900001 in words is "one million, nine hundred thousand, one".