21342002261 has 2 divisors, whose sum is σ = 21342002262. Its totient is φ = 21342002260.

The previous prime is 21342002221. The next prime is 21342002267. The reversal of 21342002261 is 16220024312.

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., 13599058225 + 7742944036 = 116615^2 + 87994^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21342002261 is a prime.

It is a super-2 number, since 2×21342002261² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21342002267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10671001130 + 10671001131.

It is an arithmetic number, because the mean of its divisors is an integer number (10671001131).

Almost surely, 2^21342002261 is an apocalyptic number.

It is an amenable number.

21342002261 is a deficient number, since it is larger than the sum of its proper divisors (1).

21342002261 is an equidigital number, since it uses as much as digits as its factorization.

21342002261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 21342002261 its reverse (16220024312), we get a palindrome (37562026573).

The spelling of 21342002261 in words is "twenty-one billion, three hundred forty-two million, two thousand, two hundred sixty-one".