51539194642 has 8 divisors (see below), whose sum is σ = 83255622156. Its totient is φ = 23787320592.

The previous prime is 51539194639. The next prime is 51539194697. The reversal of 51539194642 is 24649193515.

It can be written as a sum of positive squares in 2 ways, for example, as 51529454001 + 9740641 = 227001^2 + 3121^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-3 number, since 3×51539194642³ (a number of 33 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 991138333 + ... + 991138384.

Almost surely, 2^51539194642 is an apocalyptic number.

51539194642 is a deficient number, since it is larger than the sum of its proper divisors (31716427514).

51539194642 is a wasteful number, since it uses less digits than its factorization.

51539194642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1982276732.

The product of its digits is 1166400, while the sum is 49.

The spelling of 51539194642 in words is "fifty-one billion, five hundred thirty-nine million, one hundred ninety-four thousand, six hundred forty-two".