51387037521 has 8 divisors (see below), whose sum is σ = 72546405984. Its totient is φ = 32242847040.

The previous prime is 51387037477. The next prime is 51387037543. The reversal of 51387037521 is 12573078315.

It is a happy number.

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

It is not a de Polignac number, because 51387037521 - 2¹⁷ = 51386906449 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (51387037921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 503794435 + ... + 503794536.

It is an arithmetic number, because the mean of its divisors is an integer number (9068300748).

Almost surely, 2^51387037521 is an apocalyptic number.

51387037521 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

51387037521 is a deficient number, since it is larger than the sum of its proper divisors (21159368463).

51387037521 is a wasteful number, since it uses less digits than its factorization.

51387037521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1007588991.

The product of its (nonzero) digits is 176400, while the sum is 42.

The spelling of 51387037521 in words is "fifty-one billion, three hundred eighty-seven million, thirty-seven thousand, five hundred twenty-one".