2405621 has 2 divisors, whose sum is σ = 2405622. Its totient is φ = 2405620.

The previous prime is 2405591. The next prime is 2405633. The reversal of 2405621 is 1265042.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2283121 + 122500 = 1511^2 + 350^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2405621 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2405593 and 2405602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2405651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1202810 + 1202811.

It is an arithmetic number, because the mean of its divisors is an integer number (1202811).

2^2405621 is an apocalyptic number.

It is an amenable number.

2405621 is a deficient number, since it is larger than the sum of its proper divisors (1).

2405621 is an equidigital number, since it uses as much as digits as its factorization.

2405621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 2405621 is about 1551.0064474399. The cubic root of 2405621 is about 133.9910330377.

Subtracting from 2405621 its sum of digits (20), we obtain a square (2405601 = 1551²).

The spelling of 2405621 in words is "two million, four hundred five thousand, six hundred twenty-one".