516001221 has 48 divisors (see below), whose sum is σ = 837345600. Its totient is φ = 304280064.

The previous prime is 516001217. The next prime is 516001301. The reversal of 516001221 is 122100615.

516001221 is a `hidden beast` number, since 51 + 600 + 12 + 2 + 1 = 666.

It is not a de Polignac number, because 516001221 - 2² = 516001217 is a prime.

516001221 is a modest number, since divided by 1221 gives 516 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 516001194 and 516001203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (516001201) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 403435 + ... + 404711.

It is an arithmetic number, because the mean of its divisors is an integer number (17444700).

Almost surely, 2^516001221 is an apocalyptic number.

516001221 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

516001221 is a deficient number, since it is larger than the sum of its proper divisors (321344379).

516001221 is a wasteful number, since it uses less digits than its factorization.

516001221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1458 (or 1455 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 516001221 is about 22715.6602589491. The cubic root of 516001221 is about 802.0785640579.

Adding to 516001221 its reverse (122100615), we get a palindrome (638101836).

The spelling of 516001221 in words is "five hundred sixteen million, one thousand, two hundred twenty-one".