1001210261 has 2 divisors, whose sum is σ = 1001210262. Its totient is φ = 1001210260.

The previous prime is 1001210251. The next prime is 1001210267. The reversal of 1001210261 is 1620121001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 949009636 + 52200625 = 30806^2 + 7225^2 .

It is an emirp because it is prime and its reverse (1620121001) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1001210261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1001210267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500605130 + 500605131.

It is an arithmetic number, because the mean of its divisors is an integer number (500605131).

Almost surely, 2^1001210261 is an apocalyptic number.

It is an amenable number.

1001210261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001210261 is an equidigital number, since it uses as much as digits as its factorization.

1001210261 is an evil number, because the sum of its binary digits is even.

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

The square root of 1001210261 is about 31641.9067219408. The cubic root of 1001210261 is about 1000.4032576947.

Adding to 1001210261 its reverse (1620121001), we get a palindrome (2621331262).

The spelling of 1001210261 in words is "one billion, one million, two hundred ten thousand, two hundred sixty-one".