65561672 has 48 divisors (see below), whose sum is σ = 136817100. Its totient is φ = 29427200.

The previous prime is 65561653. The next prime is 65561681. The reversal of 65561672 is 27616556.

It can be written as a sum of positive squares in 2 ways, for example, as 48636676 + 16924996 = 6974^2 + 4114^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 85772 + ... + 86532.

Almost surely, 2^65561672 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 65561672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68408550).

65561672 is an abundant number, since it is smaller than the sum of its proper divisors (71255428).

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

65561672 is a wasteful number, since it uses less digits than its factorization.

65561672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878 (or 863 counting only the distinct ones).

The product of its digits is 75600, while the sum is 38.

The square root of 65561672 is about 8097.0162405666. The cubic root of 65561672 is about 403.2273734513.

Subtracting from 65561672 its reverse (27616556), we obtain a triangular number (37945116 = T₈₇₁₁).

It can be divided in two parts, 6556 and 1672, that added together give a palindrome (8228).

The spelling of 65561672 in words is "sixty-five million, five hundred sixty-one thousand, six hundred seventy-two".