2103145661 has 2 divisors, whose sum is σ = 2103145662. Its totient is φ = 2103145660.

The previous prime is 2103145621. The next prime is 2103145673. The reversal of 2103145661 is 1665413012.

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., 1423552900 + 679592761 = 37730^2 + 26069^2 .

It is a cyclic number.

It is not a de Polignac number, because 2103145661 - 2¹⁴ = 2103129277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2103145621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1051572830 + 1051572831.

It is an arithmetic number, because the mean of its divisors is an integer number (1051572831).

Almost surely, 2^2103145661 is an apocalyptic number.

It is an amenable number.

2103145661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2103145661 is an equidigital number, since it uses as much as digits as its factorization.

2103145661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 2103145661 is about 45860.0660815049. The cubic root of 2103145661 is about 1281.2182535985.

Adding to 2103145661 its reverse (1665413012), we get a palindrome (3768558673).

The spelling of 2103145661 in words is "two billion, one hundred three million, one hundred forty-five thousand, six hundred sixty-one".