2921861 has 2 divisors, whose sum is σ = 2921862. Its totient is φ = 2921860.

The previous prime is 2921819. The next prime is 2921869. The reversal of 2921861 is 1681292.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2825761 + 96100 = 1681^2 + 310^2 .

It is a cyclic number.

It is not a de Polignac number, because 2921861 - 2¹⁰ = 2920837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2921869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1460930 + 1460931.

It is an arithmetic number, because the mean of its divisors is an integer number (1460931).

2^2921861 is an apocalyptic number.

It is an amenable number.

2921861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2921861 is an equidigital number, since it uses as much as digits as its factorization.

2921861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 29.

The square root of 2921861 is about 1709.3451962667. The cubic root of 2921861 is about 142.9617482900.

The spelling of 2921861 in words is "two million, nine hundred twenty-one thousand, eight hundred sixty-one".