6663961 has 2 divisors, whose sum is σ = 6663962. Its totient is φ = 6663960.

The previous prime is 6663941. The next prime is 6663971. The reversal of 6663961 is 1693666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6031936 + 632025 = 2456^2 + 795^2 .

It is a cyclic number.

It is not a de Polignac number, because 6663961 - 2¹³ = 6655769 is a prime.

It is a Chen prime.

6663961 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 6663961.

It is not a weakly prime, because it can be changed into another prime (6663901) 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, 3331980 + 3331981.

It is an arithmetic number, because the mean of its divisors is an integer number (3331981).

Almost surely, 2^6663961 is an apocalyptic number.

It is an amenable number.

6663961 is a deficient number, since it is larger than the sum of its proper divisors (1).

6663961 is an equidigital number, since it uses as much as digits as its factorization.

6663961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 37.

The square root of 6663961 is about 2581.4648942025. The cubic root of 6663961 is about 188.1817410328.

The spelling of 6663961 in words is "six million, six hundred sixty-three thousand, nine hundred sixty-one".