65861870400 has 252 divisors, whose sum is σ = 238508168652. Its totient is φ = 17231585280.

The previous prime is 65861870381. The next prime is 65861870467. The reversal of 65861870400 is 407816856.

It is a happy number.

65861870400 is a `hidden beast` number, since 65 + 8 + 6 + 187 + 0 + 400 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 6193060416 + 59668809984 = 78696^2 + 244272^2 .

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 720052 + ... + 806348.

Almost surely, 2^65861870400 is an apocalyptic number.

65861870400 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 65861870400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119254084326).

65861870400 is an abundant number, since it is smaller than the sum of its proper divisors (172646298252).

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

65861870400 is a wasteful number, since it uses less digits than its factorization.

65861870400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86378 (or 86360 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The spelling of 65861870400 in words is "sixty-five billion, eight hundred sixty-one million, eight hundred seventy thousand, four hundred".