8791621 has 4 divisors (see below), whose sum is σ = 8836000. Its totient is φ = 8747244.

The previous prime is 8791603. The next prime is 8791637. The reversal of 8791621 is 1261978.

It is a happy number.

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 not a de Polignac number, because 8791621 - 2⁷ = 8791493 is a prime.

It is a Duffinian number.

8791621 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8791121) 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, 21891 + ... + 22288.

It is an arithmetic number, because the mean of its divisors is an integer number (2209000).

Almost surely, 2^8791621 is an apocalyptic number.

It is an amenable number.

8791621 is a deficient number, since it is larger than the sum of its proper divisors (44379).

8791621 is a wasteful number, since it uses less digits than its factorization.

8791621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44378.

The product of its digits is 6048, while the sum is 34.

The square root of 8791621 is about 2965.0667783374. The cubic root of 8791621 is about 206.3904759567.

It can be divided in two parts, 879 and 1621, that added together give a square (2500 = 50²).

The spelling of 8791621 in words is "eight million, seven hundred ninety-one thousand, six hundred twenty-one".