51661526400 has 576 divisors, whose sum is σ = 202128067440. Its totient is φ = 12460032000.

The previous prime is 51661526359. The next prime is 51661526431. The reversal of 51661526400 is 462516615.

51661526400 is a `hidden beast` number, since 5 + 1 + 6 + 6 + 1 + 5 + 2 + 640 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 99158140 + ... + 99158660.

Almost surely, 2^51661526400 is an apocalyptic number.

51661526400 is a gapful number since it is divisible by the number (50) 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 51661526400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101064033720).

51661526400 is an abundant number, since it is smaller than the sum of its proper divisors (150466541040).

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

51661526400 is a wasteful number, since it uses less digits than its factorization.

51661526400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 875 (or 855 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The spelling of 51661526400 in words is "fifty-one billion, six hundred sixty-one million, five hundred twenty-six thousand, four hundred".