3955621 has 2 divisors, whose sum is σ = 3955622. Its totient is φ = 3955620.

The previous prime is 3955603. The next prime is 3955643. The reversal of 3955621 is 1265593.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2842596 + 1113025 = 1686^2 + 1055^2 .

It is a cyclic number.

It is not a de Polignac number, because 3955621 - 2⁷ = 3955493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3955691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1977810 + 1977811.

It is an arithmetic number, because the mean of its divisors is an integer number (1977811).

Almost surely, 2^3955621 is an apocalyptic number.

It is an amenable number.

3955621 is a deficient number, since it is larger than the sum of its proper divisors (1).

3955621 is an equidigital number, since it uses as much as digits as its factorization.

3955621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8100, while the sum is 31.

The square root of 3955621 is about 1988.8743047262. The cubic root of 3955621 is about 158.1508600240.

The spelling of 3955621 in words is "three million, nine hundred fifty-five thousand, six hundred twenty-one".