2015621 has 2 divisors, whose sum is σ = 2015622. Its totient is φ = 2015620.

The previous prime is 2015609. The next prime is 2015627. The reversal of 2015621 is 1265102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1932100 + 83521 = 1390^2 + 289^2 .

It is a cyclic number.

It is not a de Polignac number, because 2015621 - 2⁶ = 2015557 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2015621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2015627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1007810 + 1007811.

It is an arithmetic number, because the mean of its divisors is an integer number (1007811).

2^2015621 is an apocalyptic number.

It is an amenable number.

2015621 is a deficient number, since it is larger than the sum of its proper divisors (1).

2015621 is an equidigital number, since it uses as much as digits as its factorization.

2015621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 2015621 is about 1419.7256777279. The cubic root of 2015621 is about 126.3192751201.

The spelling of 2015621 in words is "two million, fifteen thousand, six hundred twenty-one".