51315390 has 128 divisors (see below), whose sum is σ = 164736000. Its totient is φ = 11104128.

The previous prime is 51315389. The next prime is 51315391. The reversal of 51315390 is 9351315.

51315390 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (51315389) and next prime (51315391).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51315391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 35196 + ... + 36624.

It is an arithmetic number, because the mean of its divisors is an integer number (1287000).

Almost surely, 2^51315390 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51315390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82368000).

51315390 is an abundant number, since it is smaller than the sum of its proper divisors (113420610).

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

51315390 is a wasteful number, since it uses less digits than its factorization.

51315390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1471 (or 1465 counting only the distinct ones).

The product of its (nonzero) digits is 2025, while the sum is 27.

The square root of 51315390 is about 7163.4761114978. The cubic root of 51315390 is about 371.6058520439.

The spelling of 51315390 in words is "fifty-one million, three hundred fifteen thousand, three hundred ninety".