51891128490 has 64 divisors (see below), whose sum is σ = 127566692352. Its totient is φ = 13501857600.

The previous prime is 51891128459. The next prime is 51891128503. The reversal of 51891128490 is 9482119815.

It is a happy number.

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 31 ways as a sum of consecutive naturals, for example, 1258095 + ... + 1298685.

It is an arithmetic number, because the mean of its divisors is an integer number (1993229568).

Almost surely, 2^51891128490 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51891128490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63783346176).

51891128490 is an abundant number, since it is smaller than the sum of its proper divisors (75675563862).

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

51891128490 is a wasteful number, since it uses less digits than its factorization.

51891128490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41635.

The product of its (nonzero) digits is 207360, while the sum is 48.

The spelling of 51891128490 in words is "fifty-one billion, eight hundred ninety-one million, one hundred twenty-eight thousand, four hundred ninety".