2011551 has 4 divisors (see below), whose sum is σ = 2682072. Its totient is φ = 1341032.

The previous prime is 2011543. The next prime is 2011561. The reversal of 2011551 is 1551102.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2011551 - 2³ = 2011543 is a prime.

It is a D-number.

2011551 is a lucky number.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 2011551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2011531) 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, 335256 + ... + 335261.

It is an arithmetic number, because the mean of its divisors is an integer number (670518).

2^2011551 is an apocalyptic number.

2011551 is a deficient number, since it is larger than the sum of its proper divisors (670521).

2011551 is an equidigital number, since it uses as much as digits as its factorization.

2011551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670520.

The product of its (nonzero) digits is 50, while the sum is 15.

The square root of 2011551 is about 1418.2915779204. The cubic root of 2011551 is about 126.2341953225.

Adding to 2011551 its reverse (1551102), we get a palindrome (3562653).

The spelling of 2011551 in words is "two million, eleven thousand, five hundred fifty-one".