6661631 has 4 divisors (see below), whose sum is σ = 6774600. Its totient is φ = 6548664.

The previous prime is 6661601. The next prime is 6661643. The reversal of 6661631 is 1361666.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6661631 is a prime.

It is a super-2 number, since 2×6661631² = 88754655160322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6661594 and 6661603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661601) 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, 56396 + ... + 56513.

It is an arithmetic number, because the mean of its divisors is an integer number (1693650).

Almost surely, 2^6661631 is an apocalyptic number.

6661631 is a deficient number, since it is larger than the sum of its proper divisors (112969).

6661631 is a wasteful number, since it uses less digits than its factorization.

6661631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112968.

The product of its digits is 3888, while the sum is 29.

The square root of 6661631 is about 2581.0135605998. The cubic root of 6661631 is about 188.1598064022.

The spelling of 6661631 in words is "six million, six hundred sixty-one thousand, six hundred thirty-one".