216401460021 has 6 divisors (see below), whose sum is σ = 312579886710. Its totient is φ = 144267640008.

The previous prime is 216401460017. The next prime is 216401460049. The reversal of 216401460021 is 120064104612.

216401460021 is a `hidden beast` number, since 2 + 1 + 6 + 40 + 14 + 600 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 203616635121 + 12784824900 = 451239^2 + 113070^2 .

It is not a de Polignac number, because 216401460021 - 2² = 216401460017 is a prime.

It is a super-2 number, since 2×216401460021² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216401460071) 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 5 ways as a sum of consecutive naturals, for example, 12022303326 + ... + 12022303343.

It is an arithmetic number, because the mean of its divisors is an integer number (52096647785).

Almost surely, 2^216401460021 is an apocalyptic number.

It is an amenable number.

216401460021 is a deficient number, since it is larger than the sum of its proper divisors (96178426689).

216401460021 is a wasteful number, since it uses less digits than its factorization.

216401460021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24044606675 (or 24044606672 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

Adding to 216401460021 its reverse (120064104612), we get a palindrome (336465564633).

The spelling of 216401460021 in words is "two hundred sixteen billion, four hundred one million, four hundred sixty thousand, twenty-one".