2620661 has 2 divisors, whose sum is σ = 2620662. Its totient is φ = 2620660.

The previous prime is 2620637. The next prime is 2620663. The reversal of 2620661 is 1660262.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2592100 + 28561 = 1610^2 + 169^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2620661 is a prime.

Together with 2620663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2620663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1310330 + 1310331.

It is an arithmetic number, because the mean of its divisors is an integer number (1310331).

2^2620661 is an apocalyptic number.

It is an amenable number.

2620661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2620661 is an equidigital number, since it uses as much as digits as its factorization.

2620661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 2620661 is about 1618.8455763290. The cubic root of 2620661 is about 137.8701607309.

The spelling of 2620661 in words is "two million, six hundred twenty thousand, six hundred sixty-one".