721430131 has 2 divisors, whose sum is σ = 721430132. Its totient is φ = 721430130.

The previous prime is 721430113. The next prime is 721430153. The reversal of 721430131 is 131034127.

Together with previous prime (721430113) it forms an Ormiston pair, because they use the same digits, order apart.

It is an a-pointer prime, because the next prime (721430153) can be obtained adding 721430131 to its sum of digits (22).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721430131 is a prime.

It is a super-2 number, since 2×721430131² = 1040922867829354322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (721430191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360715065 + 360715066.

It is an arithmetic number, because the mean of its divisors is an integer number (360715066).

Almost surely, 2^721430131 is an apocalyptic number.

721430131 is a deficient number, since it is larger than the sum of its proper divisors (1).

721430131 is an equidigital number, since it uses as much as digits as its factorization.

721430131 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 721430131 is about 26859.4514277563. The cubic root of 721430131 is about 896.8739823806.

Adding to 721430131 its reverse (131034127), we get a palindrome (852464258).

The spelling of 721430131 in words is "seven hundred twenty-one million, four hundred thirty thousand, one hundred thirty-one".