725122661 has 2 divisors, whose sum is σ = 725122662. Its totient is φ = 725122660.

The previous prime is 725122613. The next prime is 725122663. The reversal of 725122661 is 166221527.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 515017636 + 210105025 = 22694^2 + 14495^2 .

It is a cyclic number.

It is not a de Polignac number, because 725122661 - 2²² = 720928357 is a prime.

Together with 725122663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (725122663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 362561330 + 362561331.

It is an arithmetic number, because the mean of its divisors is an integer number (362561331).

Almost surely, 2^725122661 is an apocalyptic number.

It is an amenable number.

725122661 is a deficient number, since it is larger than the sum of its proper divisors (1).

725122661 is an equidigital number, since it uses as much as digits as its factorization.

725122661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10080, while the sum is 32.

The square root of 725122661 is about 26928.1016969262. The cubic root of 725122661 is about 898.4015499875.

The spelling of 725122661 in words is "seven hundred twenty-five million, one hundred twenty-two thousand, six hundred sixty-one".