8419721 has 4 divisors (see below), whose sum is σ = 8598912. Its totient is φ = 8240532.

The previous prime is 8419661. The next prime is 8419727. The reversal of 8419721 is 1279148.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 8419721 - 2¹⁴ = 8403337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8419727) 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, 89525 + ... + 89618.

It is an arithmetic number, because the mean of its divisors is an integer number (2149728).

Almost surely, 2^8419721 is an apocalyptic number.

It is an amenable number.

8419721 is a deficient number, since it is larger than the sum of its proper divisors (179191).

8419721 is a wasteful number, since it uses less digits than its factorization.

8419721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179190.

The product of its digits is 4032, while the sum is 32.

The square root of 8419721 is about 2901.6755504363. The cubic root of 8419721 is about 203.4382291938.

The spelling of 8419721 in words is "eight million, four hundred nineteen thousand, seven hundred twenty-one".