2101001261 has 2 divisors, whose sum is σ = 2101001262. Its totient is φ = 2101001260.

The previous prime is 2101001239. The next prime is 2101001297. The reversal of 2101001261 is 1621001012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2060615236 + 40386025 = 45394^2 + 6355^2 .

It is a cyclic number.

It is not a de Polignac number, because 2101001261 - 2⁶ = 2101001197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2101001561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050500630 + 1050500631.

It is an arithmetic number, because the mean of its divisors is an integer number (1050500631).

Almost surely, 2^2101001261 is an apocalyptic number.

It is an amenable number.

2101001261 is a deficient number, since it is larger than the sum of its proper divisors (1).

2101001261 is an equidigital number, since it uses as much as digits as its factorization.

2101001261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 14.

The square root of 2101001261 is about 45836.6803008246. The cubic root of 2101001261 is about 1280.7826555033.

Adding to 2101001261 its reverse (1621001012), we get a palindrome (3722002273).

The spelling of 2101001261 in words is "two billion, one hundred one million, one thousand, two hundred sixty-one".