2661641 has 2 divisors, whose sum is σ = 2661642. Its totient is φ = 2661640.

The previous prime is 2661611. The next prime is 2661643. The reversal of 2661641 is 1461662.

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., 2468041 + 193600 = 1571^2 + 440^2 .

It is a cyclic number.

It is not a de Polignac number, because 2661641 - 2¹⁴ = 2645257 is a prime.

Together with 2661643, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p₁₉₄₀₅₇ and since 2661641 and 194057 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2661641.

It is not a weakly prime, because it can be changed into another prime (2661643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1330820 + 1330821.

It is an arithmetic number, because the mean of its divisors is an integer number (1330821).

2^2661641 is an apocalyptic number.

It is an amenable number.

2661641 is a deficient number, since it is larger than the sum of its proper divisors (1).

2661641 is an equidigital number, since it uses as much as digits as its factorization.

2661641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 26.

The square root of 2661641 is about 1631.4536462922. The cubic root of 2661641 is about 138.5850850202.

The spelling of 2661641 in words is "two million, six hundred sixty-one thousand, six hundred forty-one".