8722421 has 8 divisors (see below), whose sum is σ = 9054144. Its totient is φ = 8396640.

The previous prime is 8722409. The next prime is 8722423. The reversal of 8722421 is 1242278.

8722421 = T₁₇₃ + T₁₇₄ + ... + T₃₈₅.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8722421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8722423) 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 7 ways as a sum of consecutive naturals, for example, 1625 + ... + 4481.

It is an arithmetic number, because the mean of its divisors is an integer number (1131768).

Almost surely, 2^8722421 is an apocalyptic number.

It is an amenable number.

8722421 is a deficient number, since it is larger than the sum of its proper divisors (331723).

8722421 is a wasteful number, since it uses less digits than its factorization.

8722421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2971.

The product of its digits is 1792, while the sum is 26.

The square root of 8722421 is about 2953.3745106234. The cubic root of 8722421 is about 205.8475401290.

Adding to 8722421 its reverse (1242278), we get a palindrome (9964699).

It can be divided in two parts, 872 and 2421, that multiplied together give a palindrome (2111112).

The spelling of 8722421 in words is "eight million, seven hundred twenty-two thousand, four hundred twenty-one".