249039961 has 9 divisors (see below), whose sum is σ = 255662901. Its totient is φ = 242585532.

The previous prime is 249039949. The next prime is 249039971. The reversal of 249039961 is 169930942.

The square root of 249039961 is 15781.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 249039961 - 2¹⁵ = 249007193 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (249039911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 678400 + ... + 678766.

It is an arithmetic number, because the mean of its divisors is an integer number (28406989).

Almost surely, 2^249039961 is an apocalyptic number.

249039961 is the 15781-st square number.

249039961 is the 7891-st centered octagonal number.

It is an amenable number.

249039961 is a deficient number, since it is larger than the sum of its proper divisors (6622940).

249039961 is an frugal number, since it uses more digits than its factorization.

249039961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820 (or 410 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 43.

The cubic root of 249039961 is about 629.1531082986.

Multiplying 249039961 by its product of nonzero digits (104976), we get a square (26143218945936 = 5113044²).

It can be divided in two parts, 249039 and 961, that added together give a square (250000 = 500²).

The spelling of 249039961 in words is "two hundred forty-nine million, thirty-nine thousand, nine hundred sixty-one".