251490 has 32 divisors (see below), whose sum is σ = 616896. Its totient is φ = 65600.

The previous prime is 251483. The next prime is 251491. The reversal of 251490 is 94152.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (251491) by changing a digit.

251490 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 15 ways as a sum of consecutive naturals, for example, 2440 + ... + 2540.

It is an arithmetic number, because the mean of its divisors is an integer number (19278).

2²⁵¹⁴⁹⁰ is an apocalyptic number.

251490 is an abundant number, since it is smaller than the sum of its proper divisors (365406).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

251490 is a wasteful number, since it uses less digits than its factorization.

251490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 251490 is about 501.4877864914. The cubic root of 251490 is about 63.1209568368.

It can be divided in two parts, 251 and 490, that added together give a triangular number (741 = T₃₈).

The spelling of 251490 in words is "two hundred fifty-one thousand, four hundred ninety".