721242420131 has 2 divisors, whose sum is σ = 721242420132. Its totient is φ = 721242420130.

The previous prime is 721242420037. The next prime is 721242420167. The reversal of 721242420131 is 131024242127.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (131024242127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 721242420131 - 2³⁸ = 446364513187 is a prime.

It is a super-3 number, since 3×721242420131³ (a number of 37 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 721242420094 and 721242420103.

It is not a weakly prime, because it can be changed into another prime (721242420331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360621210065 + 360621210066.

It is an arithmetic number, because the mean of its divisors is an integer number (360621210066).

Almost surely, 2^721242420131 is an apocalyptic number.

721242420131 is a deficient number, since it is larger than the sum of its proper divisors (1).

721242420131 is an equidigital number, since it uses as much as digits as its factorization.

721242420131 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5376, while the sum is 29.

Adding to 721242420131 its reverse (131024242127), we get a palindrome (852266662258).

The spelling of 721242420131 in words is "seven hundred twenty-one billion, two hundred forty-two million, four hundred twenty thousand, one hundred thirty-one".