251398 has 8 divisors (see below), whose sum is σ = 430992. Its totient is φ = 107736.

The previous prime is 251393. The next prime is 251417. The reversal of 251398 is 893152.

251398 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251393) by changing a digit.

251398 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8965 + ... + 8992.

It is an arithmetic number, because the mean of its divisors is an integer number (53874).

2²⁵¹³⁹⁸ is an apocalyptic number.

251398 is a deficient number, since it is larger than the sum of its proper divisors (179594).

251398 is a wasteful number, since it uses less digits than its factorization.

251398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17966.

The product of its digits is 2160, while the sum is 28.

The square root of 251398 is about 501.3960510415. The cubic root of 251398 is about 63.1132589345.

The spelling of 251398 in words is "two hundred fifty-one thousand, three hundred ninety-eight".