65661235200 has 1248 divisors, whose sum is σ = 280816312320. Its totient is φ = 14863564800.

The previous prime is 65661235163. The next prime is 65661235207. The reversal of 65661235200 is 253216656.

It is a happy number.

65661235200 is a `hidden beast` number, since 6 + 5 + 6 + 6 + 123 + 520 + 0 = 666.

It is a super-2 number, since 2×65661235200² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65661235207) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 517017537 + ... + 517017663.

Almost surely, 2^65661235200 is an apocalyptic number.

65661235200 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 65661235200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140408156160).

65661235200 is an abundant number, since it is smaller than the sum of its proper divisors (215155077120).

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

65661235200 is a wasteful number, since it uses less digits than its factorization.

65661235200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198 (or 165 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The spelling of 65661235200 in words is "sixty-five billion, six hundred sixty-one million, two hundred thirty-five thousand, two hundred".