51250000 has 80 divisors (see below), whose sum is σ = 127148112. Its totient is φ = 20000000.

The previous prime is 51249997. The next prime is 51250007. The reversal of 51250000 is 5215.

It can be written as a sum of positive squares in 8 ways, for example, as 25969216 + 25280784 = 5096^2 + 5028^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51250007) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1249980 + ... + 1250020.

Almost surely, 2^51250000 is an apocalyptic number.

51250000 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 51250000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63574056).

51250000 is an abundant number, since it is smaller than the sum of its proper divisors (75898112).

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

51250000 is an frugal number, since it uses more digits than its factorization.

51250000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84 (or 48 counting only the distinct ones).

The product of its (nonzero) digits is 50, while the sum is 13.

The square root of 51250000 is about 7158.9105316382. The cubic root of 51250000 is about 371.4479420723.

Adding to 51250000 its reverse (5215), we get a palindrome (51255215).

It can be divided in two parts, 5 and 1250000, that multiplied together give a 4-th power (6250000 = 50⁴).

The spelling of 51250000 in words is "fifty-one million, two hundred fifty thousand".