51289380 has 72 divisors (see below), whose sum is σ = 157090752. Its totient is φ = 13544256.

The previous prime is 51289339. The next prime is 51289387. The reversal of 51289380 is 8398215.

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

It is not an unprimeable number, because it can be changed into a prime (51289387) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17929 + ... + 20591.

It is an arithmetic number, because the mean of its divisors is an integer number (2181816).

Almost surely, 2^51289380 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51289380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78545376).

51289380 is an abundant number, since it is smaller than the sum of its proper divisors (105801372).

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

51289380 is a wasteful number, since it uses less digits than its factorization.

51289380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2785 (or 2780 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 51289380 is about 7161.6604219971. The cubic root of 51289380 is about 371.5430567064.

The spelling of 51289380 in words is "fifty-one million, two hundred eighty-nine thousand, three hundred eighty".