65851712640 has 512 divisors, whose sum is σ = 267321600000. Its totient is φ = 15007887360.

The previous prime is 65851712639. The next prime is 65851712651. The reversal of 65851712640 is 4621715856.

65851712640 is a `hidden beast` number, since 6 + 5 + 8 + 517 + 126 + 4 + 0 = 666.

It is a super-2 number, since 2×65851712640² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 60358495 + ... + 60359585.

It is an arithmetic number, because the mean of its divisors is an integer number (522112500).

Almost surely, 2^65851712640 is an apocalyptic number.

65851712640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65851712640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133660800000).

65851712640 is an abundant number, since it is smaller than the sum of its proper divisors (201469887360).

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

65851712640 is a wasteful number, since it uses less digits than its factorization.

65851712640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1625 (or 1607 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The spelling of 65851712640 in words is "sixty-five billion, eight hundred fifty-one million, seven hundred twelve thousand, six hundred forty".