65905840 has 160 divisors (see below), whose sum is σ = 205986816. Its totient is φ = 18938880.

The previous prime is 65905837. The next prime is 65905859. The reversal of 65905840 is 4850956.

It is a super-2 number, since 2×65905840² = 8687159492211200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 65905840.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 79669 + ... + 80491.

Almost surely, 2^65905840 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 65905840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102993408).

65905840 is an abundant number, since it is smaller than the sum of its proper divisors (140080976).

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

65905840 is a wasteful number, since it uses less digits than its factorization.

65905840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 867 (or 861 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 37.

The square root of 65905840 is about 8118.2411888290. The cubic root of 65905840 is about 403.9317271815.

The spelling of 65905840 in words is "sixty-five million, nine hundred five thousand, eight hundred forty".