65531620 has 72 divisors (see below), whose sum is σ = 174666240. Its totient is φ = 20422080.

The previous prime is 65531581. The next prime is 65531633. The reversal of 65531620 is 2613556.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7741 + ... + 13819.

It is an arithmetic number, because the mean of its divisors is an integer number (2425920).

Almost surely, 2^65531620 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 65531620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87333120).

65531620 is an abundant number, since it is smaller than the sum of its proper divisors (109134620).

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

65531620 is a wasteful number, since it uses less digits than its factorization.

65531620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6113 (or 6104 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 65531620 is about 8095.1602825392. The cubic root of 65531620 is about 403.1657539072.

The spelling of 65531620 in words is "sixty-five million, five hundred thirty-one thousand, six hundred twenty".