8421631 has 4 divisors (see below), whose sum is σ = 8452312. Its totient is φ = 8390952.

The previous prime is 8421619. The next prime is 8421641. The reversal of 8421631 is 1361248.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 8421631 - 2¹³ = 8413439 is a prime.

It is a super-2 number, since 2×8421631² = 141847737400322, which contains 22 as substring.

It is a d-powerful number, because it can be written as 8⁵ + 4 + 2²³ + 1 + 6 + 3⁵ + 1 .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 8421596 and 8421605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8421641) 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, 14925 + ... + 15478.

It is an arithmetic number, because the mean of its divisors is an integer number (2113078).

Almost surely, 2^8421631 is an apocalyptic number.

8421631 is a deficient number, since it is larger than the sum of its proper divisors (30681).

8421631 is a wasteful number, since it uses less digits than its factorization.

8421631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30680.

The product of its digits is 1152, while the sum is 25.

The square root of 8421631 is about 2902.0046519604. The cubic root of 8421631 is about 203.4536112411.

Adding to 8421631 its reverse (1361248), we get a palindrome (9782879).

The spelling of 8421631 in words is "eight million, four hundred twenty-one thousand, six hundred thirty-one".