65155840 has 72 divisors (see below), whose sum is σ = 157837680. Its totient is φ = 25767936.

The previous prime is 65155829. The next prime is 65155841. The reversal of 65155840 is 4855156.

It is a happy number.

It is a super-2 number, since 2×65155840² = 8490566972211200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 65155796 and 65155805.

It is not an unprimeable number, because it can be changed into a prime (65155841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 139287 + ... + 139753.

It is an arithmetic number, because the mean of its divisors is an integer number (2192190).

Almost surely, 2^65155840 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 65155840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78918840).

65155840 is an abundant number, since it is smaller than the sum of its proper divisors (92681840).

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

65155840 is a wasteful number, since it uses less digits than its factorization.

65155840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 597 (or 583 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 34.

The square root of 65155840 is about 8071.9167488274. The cubic root of 65155840 is about 402.3936475565.

The spelling of 65155840 in words is "sixty-five million, one hundred fifty-five thousand, eight hundred forty".