51938116865490 has 64 divisors (see below), whose sum is σ = 124772736337920. Its totient is φ = 13836692985600.

The previous prime is 51938116865447. The next prime is 51938116865491. The reversal of 51938116865490 is 9456861183915.

It is a happy number.

It is a Smith number, since the sum of its digits (66) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (51938116865491) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 942434056 + ... + 942489164.

It is an arithmetic number, because the mean of its divisors is an integer number (1949574005280).

Almost surely, 2^{51938116865490} is an apocalyptic number.

51938116865490 is an abundant number, since it is smaller than the sum of its proper divisors (72834619472430).

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

51938116865490 is a wasteful number, since it uses less digits than its factorization.

51938116865490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85107.

The product of its (nonzero) digits is 55987200, while the sum is 66.

The spelling of 51938116865490 in words is "fifty-one trillion, nine hundred thirty-eight billion, one hundred sixteen million, eight hundred sixty-five thousand, four hundred ninety".