721689047 has 2 divisors, whose sum is σ = 721689048. Its totient is φ = 721689046.

The previous prime is 721689043. The next prime is 721689113. The reversal of 721689047 is 740986127.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 721689047 - 2² = 721689043 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 721688989 and 721689007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721689043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360844523 + 360844524.

It is an arithmetic number, because the mean of its divisors is an integer number (360844524).

Almost surely, 2^721689047 is an apocalyptic number.

721689047 is a deficient number, since it is larger than the sum of its proper divisors (1).

721689047 is an equidigital number, since it uses as much as digits as its factorization.

721689047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 169344, while the sum is 44.

The square root of 721689047 is about 26864.2708257641. The cubic root of 721689047 is about 896.9812633860.

The spelling of 721689047 in words is "seven hundred twenty-one million, six hundred eighty-nine thousand, forty-seven".