51021217 has 8 divisors (see below), whose sum is σ = 55074600. Its totient is φ = 46986240.

The previous prime is 51021197. The next prime is 51021241. The reversal of 51021217 is 71212015.

It can be written as a sum of positive squares in 4 ways, for example, as 341056 + 50680161 = 584^2 + 7119^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51021217 is a prime.

It is a super-2 number, since 2×51021217² = 5206329168322178, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51021194 and 51021203.

It is not an unprimeable number, because it can be changed into a prime (51022217) 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, 1467 + ... + 10207.

It is an arithmetic number, because the mean of its divisors is an integer number (6884325).

Almost surely, 2^51021217 is an apocalyptic number.

It is an amenable number.

51021217 is a deficient number, since it is larger than the sum of its proper divisors (4053383).

51021217 is a wasteful number, since it uses less digits than its factorization.

51021217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9203.

The product of its (nonzero) digits is 140, while the sum is 19.

The square root of 51021217 is about 7142.9137612042. The cubic root of 51021217 is about 370.8943957801.

The spelling of 51021217 in words is "fifty-one million, twenty-one thousand, two hundred seventeen".