2391621 has 4 divisors (see below), whose sum is σ = 3188832. Its totient is φ = 1594412.

The previous prime is 2391589. The next prime is 2391629. The reversal of 2391621 is 1261932.

2391621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 2391621 - 2⁵ = 2391589 is a prime.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 2391591 and 2391600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2391629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 398601 + ... + 398606.

It is an arithmetic number, because the mean of its divisors is an integer number (797208).

2^2391621 is an apocalyptic number.

It is an amenable number.

2391621 is a deficient number, since it is larger than the sum of its proper divisors (797211).

2391621 is an equidigital number, since it uses as much as digits as its factorization.

2391621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797210.

The product of its digits is 648, while the sum is 24.

The square root of 2391621 is about 1546.4866633761. The cubic root of 2391621 is about 133.7305978203.

The spelling of 2391621 in words is "two million, three hundred ninety-one thousand, six hundred twenty-one".