721375091 has 2 divisors, whose sum is σ = 721375092. Its totient is φ = 721375090.

The previous prime is 721375043. The next prime is 721375141. The reversal of 721375091 is 190573127.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 721375091 - 2¹⁴ = 721358707 is a prime.

It is not a weakly prime, because it can be changed into another prime (721375001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360687545 + 360687546.

It is an arithmetic number, because the mean of its divisors is an integer number (360687546).

Almost surely, 2^721375091 is an apocalyptic number.

721375091 is a deficient number, since it is larger than the sum of its proper divisors (1).

721375091 is an equidigital number, since it uses as much as digits as its factorization.

721375091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13230, while the sum is 35.

The square root of 721375091 is about 26858.4268154336. The cubic root of 721375091 is about 896.8511734268.

The spelling of 721375091 in words is "seven hundred twenty-one million, three hundred seventy-five thousand, ninety-one".