8721290 has 8 divisors (see below), whose sum is σ = 15698340. Its totient is φ = 3488512.

The previous prime is 8721281. The next prime is 8721299. The reversal of 8721290 is 921278.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (8721281) and next prime (8721299).

It can be written as a sum of positive squares in 2 ways, for example, as 8684809 + 36481 = 2947^2 + 191^2 .

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

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (8721299) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 436055 + ... + 436074.

Almost surely, 2^8721290 is an apocalyptic number.

8721290 is a deficient number, since it is larger than the sum of its proper divisors (6977050).

8721290 is a wasteful number, since it uses less digits than its factorization.

8721290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 872136.

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 8721290 is about 2953.1830285304. The cubic root of 8721290 is about 205.8386426134.

The spelling of 8721290 in words is "eight million, seven hundred twenty-one thousand, two hundred ninety".