51220705536 has 864 divisors, whose sum is σ = 205215637760. Its totient is φ = 12262440960.

The previous prime is 51220705499. The next prime is 51220705559. The reversal of 51220705536 is 63550702215.

51220705536 is a `hidden beast` number, since 5 + 12 + 20 + 70 + 553 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

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

It is a self number, because there is not a number n which added to its sum of digits gives 51220705536.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 76107696 + ... + 76108368.

Almost surely, 2^51220705536 is an apocalyptic number.

51220705536 is a gapful number since it is divisible by the number (56) 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 51220705536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102607818880).

51220705536 is an abundant number, since it is smaller than the sum of its proper divisors (153994932224).

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

51220705536 is a wasteful number, since it uses less digits than its factorization.

51220705536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 740 (or 709 counting only the distinct ones).

The product of its (nonzero) digits is 63000, while the sum is 36.

The spelling of 51220705536 in words is "fifty-one billion, two hundred twenty million, seven hundred five thousand, five hundred thirty-six".