721375157 has 2 divisors, whose sum is σ = 721375158. Its totient is φ = 721375156.

The previous prime is 721375141. The next prime is 721375159. The reversal of 721375157 is 751573127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 364580836 + 356794321 = 19094^2 + 18889^2 .

It is a cyclic number.

It is not a de Polignac number, because 721375157 - 2⁴ = 721375141 is a prime.

Together with 721375159, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 721375157.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721375159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360687578 + 360687579.

It is an arithmetic number, because the mean of its divisors is an integer number (360687579).

Almost surely, 2^721375157 is an apocalyptic number.

It is an amenable number.

721375157 is a deficient number, since it is larger than the sum of its proper divisors (1).

721375157 is an equidigital number, since it uses as much as digits as its factorization.

721375157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51450, while the sum is 38.

The square root of 721375157 is about 26858.4280440982. The cubic root of 721375157 is about 896.8512007784.

The spelling of 721375157 in words is "seven hundred twenty-one million, three hundred seventy-five thousand, one hundred fifty-seven".