8216621 has 4 divisors (see below), whose sum is σ = 9390432. Its totient is φ = 7042812.

The previous prime is 8216609. The next prime is 8216641. The reversal of 8216621 is 1266128.

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 8216621 - 2⁶ = 8216557 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8216641) 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, 586895 + ... + 586908.

It is an arithmetic number, because the mean of its divisors is an integer number (2347608).

Almost surely, 2^8216621 is an apocalyptic number.

It is an amenable number.

8216621 is a deficient number, since it is larger than the sum of its proper divisors (1173811).

8216621 is a wasteful number, since it uses less digits than its factorization.

8216621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1173810.

The product of its digits is 1152, while the sum is 26.

The square root of 8216621 is about 2866.4648959999. The cubic root of 8216621 is about 201.7891224795.

The spelling of 8216621 in words is "eight million, two hundred sixteen thousand, six hundred twenty-one".