61809868800 has 810 divisors, whose sum is σ = 239910274968. Its totient is φ = 15765995520.

The previous prime is 61809868793. The next prime is 61809868801. The reversal of 61809868800 is 886890816.

It is a tau number, because it is divible by the number of its divisors (810).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61809868801) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 2687385589 + ... + 2687385611.

Almost surely, 2^61809868800 is an apocalyptic number.

61809868800 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 61809868800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119955137484).

61809868800 is an abundant number, since it is smaller than the sum of its proper divisors (178100406168).

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

61809868800 is an frugal number, since it uses more digits than its factorization.

61809868800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85 (or 33 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 54.

The spelling of 61809868800 in words is "sixty-one billion, eight hundred nine million, eight hundred sixty-eight thousand, eight hundred".