51212005 has 16 divisors (see below), whose sum is σ = 66432240. Its totient is φ = 37675008.

The previous prime is 51211981. The next prime is 51212009. The reversal of 51212005 is 50021215.

It can be written as a sum of positive squares in 8 ways, for example, as 4124961 + 47087044 = 2031^2 + 6862^2 .

It is a cyclic number.

It is not a de Polignac number, because 51212005 - 2¹⁷ = 51080933 is a prime.

It is a super-2 number, since 2×51212005² = 5245338912240050, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51212005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51212009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17701 + ... + 20389.

It is an arithmetic number, because the mean of its divisors is an integer number (4152015).

Almost surely, 2^51212005 is an apocalyptic number.

It is an amenable number.

51212005 is a deficient number, since it is larger than the sum of its proper divisors (15220235).

51212005 is a wasteful number, since it uses less digits than its factorization.

51212005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3000.

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 51212005 is about 7156.2563537090. The cubic root of 51212005 is about 371.3561264387.

The spelling of 51212005 in words is "fifty-one million, two hundred twelve thousand, five".