31221249 has 8 divisors (see below), whose sum is σ = 41696832. Its totient is φ = 20779920.

The previous prime is 31221227. The next prime is 31221251. The reversal of 31221249 is 94212213.

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

It is not a de Polignac number, because 31221249 - 2¹⁹ = 30696961 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31221259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6354 + ... + 10139.

It is an arithmetic number, because the mean of its divisors is an integer number (5212104).

Almost surely, 2^31221249 is an apocalyptic number.

It is an amenable number.

31221249 is a deficient number, since it is larger than the sum of its proper divisors (10475583).

31221249 is a wasteful number, since it uses less digits than its factorization.

31221249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17127.

The product of its digits is 864, while the sum is 24.

The square root of 31221249 is about 5587.5977843793. The cubic root of 31221249 is about 314.8836355274.

It can be divided in two parts, 3122 and 1249, that added together give a triangular number (4371 = T₉₃).

The spelling of 31221249 in words is "thirty-one million, two hundred twenty-one thousand, two hundred forty-nine".