61555432800 has 144 divisors (see below), whose sum is σ = 201893452992. Its totient is φ = 16289395200.

The previous prime is 61555432781. The next prime is 61555432819. The reversal of 61555432800 is 823455516.

It is an interprime number because it is at equal distance from previous prime (61555432781) and next prime (61555432819).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 216507 + ... + 412293.

It is an arithmetic number, because the mean of its divisors is an integer number (1402037868).

Almost surely, 2^61555432800 is an apocalyptic number.

61555432800 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 61555432800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100946726496).

61555432800 is an abundant number, since it is smaller than the sum of its proper divisors (140338020192).

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

61555432800 is a wasteful number, since it uses less digits than its factorization.

61555432800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195941 (or 195928 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 39.

The spelling of 61555432800 in words is "sixty-one billion, five hundred fifty-five million, four hundred thirty-two thousand, eight hundred".