721609087 has 2 divisors, whose sum is σ = 721609088. Its totient is φ = 721609086.

The previous prime is 721609067. The next prime is 721609121. The reversal of 721609087 is 780906127.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 721609087 - 2⁷ = 721608959 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721609067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360804543 + 360804544.

It is an arithmetic number, because the mean of its divisors is an integer number (360804544).

Almost surely, 2^721609087 is an apocalyptic number.

721609087 is a deficient number, since it is larger than the sum of its proper divisors (1).

721609087 is an equidigital number, since it uses as much as digits as its factorization.

721609087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42336, while the sum is 40.

The square root of 721609087 is about 26862.7825624971. The cubic root of 721609087 is about 896.9481349581.

The spelling of 721609087 in words is "seven hundred twenty-one million, six hundred nine thousand, eighty-seven".