21180216630501 has 12 divisors (see below), whose sum is σ = 30604354592812. Its totient is φ = 14115202105536.

The previous prime is 21180216630467. The next prime is 21180216630553. The reversal of 21180216630501 is 10503661208112.

21180216630501 is a `hidden beast` number, since 2 + 1 + 1 + 8 + 0 + 2 + 16 + 630 + 5 + 0 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 17032582973025 + 4147633657476 = 4127055^2 + 2036574^2 .

It is not a de Polignac number, because 21180216630501 - 2¹¹ = 21180216628453 is a prime.

It is a super-2 number, since 2×21180216630501² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21180216630571) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 411832426 + ... + 411883851.

Almost surely, 2^{21180216630501} is an apocalyptic number.

It is an amenable number.

21180216630501 is a deficient number, since it is larger than the sum of its proper divisors (9424137962311).

21180216630501 is a wasteful number, since it uses less digits than its factorization.

21180216630501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 823719140 (or 823719137 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

Adding to 21180216630501 its reverse (10503661208112), we get a palindrome (31683877838613).

The spelling of 21180216630501 in words is "twenty-one trillion, one hundred eighty billion, two hundred sixteen million, six hundred thirty thousand, five hundred one".