51213239985 has 8 divisors (see below), whose sum is σ = 81941184000. Its totient is φ = 27313727984.

The previous prime is 51213239951. The next prime is 51213239989. The reversal of 51213239985 is 58993231215.

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

It is a cyclic number.

It is not a de Polignac number, because 51213239985 - 2¹³ = 51213231793 is a prime.

It is a super-2 number, since 2×51213239985² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51213239989) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1707107985 + ... + 1707108014.

It is an arithmetic number, because the mean of its divisors is an integer number (10242648000).

Almost surely, 2^51213239985 is an apocalyptic number.

It is an amenable number.

51213239985 is a deficient number, since it is larger than the sum of its proper divisors (30727944015).

51213239985 is a wasteful number, since it uses less digits than its factorization.

51213239985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3414216007.

The product of its digits is 583200, while the sum is 48.

The spelling of 51213239985 in words is "fifty-one billion, two hundred thirteen million, two hundred thirty-nine thousand, nine hundred eighty-five".