6421631 has 8 divisors (see below), whose sum is σ = 6822000. Its totient is φ = 6023808.

The previous prime is 6421589. The next prime is 6421637. The reversal of 6421631 is 1361246.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 6421631 - 2⁶ = 6421567 is a prime.

It is a super-2 number, since 2×6421631² = 82474689400322, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 6421597 and 6421606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6421637) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8105 + ... + 8861.

It is an arithmetic number, because the mean of its divisors is an integer number (852750).

Almost surely, 2^6421631 is an apocalyptic number.

6421631 is a deficient number, since it is larger than the sum of its proper divisors (400369).

6421631 is a wasteful number, since it uses less digits than its factorization.

6421631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1273.

The product of its digits is 864, while the sum is 23.

The square root of 6421631 is about 2534.0937236022. The cubic root of 6421631 is about 185.8724893974.

Adding to 6421631 its reverse (1361246), we get a palindrome (7782877).

The spelling of 6421631 in words is "six million, four hundred twenty-one thousand, six hundred thirty-one".