1906521 has 4 divisors (see below), whose sum is σ = 2542032. Its totient is φ = 1271012.

The previous prime is 1906511. The next prime is 1906523. The reversal of 1906521 is 1256091.

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 1906521 - 2⁷ = 1906393 is a prime.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 1906491 and 1906500.

It is not an unprimeable number, because it can be changed into a prime (1906523) 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, 317751 + ... + 317756.

It is an arithmetic number, because the mean of its divisors is an integer number (635508).

2^1906521 is an apocalyptic number.

It is an amenable number.

1906521 is a deficient number, since it is larger than the sum of its proper divisors (635511).

1906521 is an equidigital number, since it uses as much as digits as its factorization.

1906521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 635510.

The product of its (nonzero) digits is 540, while the sum is 24.

The square root of 1906521 is about 1380.7682644093. The cubic root of 1906521 is about 123.9977670427.

It can be divided in two parts, 190652 and 1, that added together give a triangular number (190653 = T₆₁₇).

The spelling of 1906521 in words is "one million, nine hundred six thousand, five hundred twenty-one".