21240216207 has 24 divisors (see below), whose sum is σ = 35095117824. Its totient is φ = 12126222864.

The previous prime is 21240216199. The next prime is 21240216247. The reversal of 21240216207 is 70261204212.

21240216207 is a `hidden beast` number, since 2 + 1 + 240 + 216 + 207 = 666.

It is not a de Polignac number, because 21240216207 - 2³ = 21240216199 is a prime.

It is a super-2 number, since 2×21240216207² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21240216247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 83343 + ... + 222320.

It is an arithmetic number, because the mean of its divisors is an integer number (1462296576).

Almost surely, 2^21240216207 is an apocalyptic number.

21240216207 is a deficient number, since it is larger than the sum of its proper divisors (13854901617).

21240216207 is a wasteful number, since it uses less digits than its factorization.

21240216207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306779 (or 306776 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The spelling of 21240216207 in words is "twenty-one billion, two hundred forty million, two hundred sixteen thousand, two hundred seven".