725981 has 2 divisors, whose sum is σ = 725982. Its totient is φ = 725980.

The previous prime is 725953. The next prime is 725983. The reversal of 725981 is 189527.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 722500 + 3481 = 850^2 + 59^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-725981 is a prime.

It is a super-2 number, since 2×725981² = 1054096824722, which contains 22 as substring.

Together with 725983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 725981.

It is not a weakly prime, because it can be changed into another prime (725983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 362990 + 362991.

It is an arithmetic number, because the mean of its divisors is an integer number (362991).

2⁷²⁵⁹⁸¹ is an apocalyptic number.

It is an amenable number.

725981 is a deficient number, since it is larger than the sum of its proper divisors (1).

725981 is an equidigital number, since it uses as much as digits as its factorization.

725981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 32.

The square root of 725981 is about 852.0451865952. The cubic root of 725981 is about 89.8755894184.

The spelling of 725981 in words is "seven hundred twenty-five thousand, nine hundred eighty-one".