4021961 has 2 divisors, whose sum is σ = 4021962. Its totient is φ = 4021960.

The previous prime is 4021949. The next prime is 4021967. The reversal of 4021961 is 1691204.

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., 4020025 + 1936 = 2005^2 + 44^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4021961 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (4021967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2010980 + 2010981.

It is an arithmetic number, because the mean of its divisors is an integer number (2010981).

Almost surely, 2^4021961 is an apocalyptic number.

It is an amenable number.

4021961 is a deficient number, since it is larger than the sum of its proper divisors (1).

4021961 is an equidigital number, since it uses as much as digits as its factorization.

4021961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 4021961 is about 2005.4827349045. The cubic root of 4021961 is about 159.0300827802.

The spelling of 4021961 in words is "four million, twenty-one thousand, nine hundred sixty-one".