51146721000 has 320 divisors, whose sum is σ = 183158735760. Its totient is φ = 13305600000.

The previous prime is 51146720987. The next prime is 51146721013. The reversal of 51146721000 is 12764115.

It is a happy number.

51146721000 is a `hidden beast` number, since 511 + 46 + 7 + 2 + 100 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (51146720987) and next prime (51146721013).

It can be written as a sum of positive squares in 8 ways, for example, as 3135776004 + 48010944996 = 55998^2 + 219114^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

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 79 ways as a sum of consecutive naturals, for example, 3313300 + ... + 3328700.

Almost surely, 2^51146721000 is an apocalyptic number.

51146721000 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 51146721000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91579367880).

51146721000 is an abundant number, since it is smaller than the sum of its proper divisors (132012014760).

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

51146721000 is a wasteful number, since it uses less digits than its factorization.

51146721000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15475 (or 15452 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The spelling of 51146721000 in words is "fifty-one billion, one hundred forty-six million, seven hundred twenty-one thousand".