6561996 has 48 divisors (see below), whose sum is σ = 17633280. Its totient is φ = 1860480.

The previous prime is 6561991. The next prime is 6562001. The reversal of 6561996 is 6991656.

It is an interprime number because it is at equal distance from previous prime (6561991) and next prime (6562001).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (6561991) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15840 + ... + 16248.

It is an arithmetic number, because the mean of its divisors is an integer number (367360).

Almost surely, 2^6561996 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6561996, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8816640).

6561996 is an abundant number, since it is smaller than the sum of its proper divisors (11071284).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6561996 is a wasteful number, since it uses less digits than its factorization.

6561996 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 614 (or 612 counting only the distinct ones).

The product of its digits is 87480, while the sum is 42.

The square root of 6561996 is about 2561.6393188738. The cubic root of 6561996 is about 187.2170166794.

It can be divided in two parts, 6561 and 996, that added together give a palindrome (7557).

The spelling of 6561996 in words is "six million, five hundred sixty-one thousand, nine hundred ninety-six".