21006684280511 has 8 divisors (see below), whose sum is σ = 21351216018048. Its totient is φ = 20662157700000.

The previous prime is 21006684280471. The next prime is 21006684280537. The reversal of 21006684280511 is 11508248660012.

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-21006684280511 is a prime.

It is a super-2 number, since 2×21006684280511² (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 (21006684210511) 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, 7400786 + ... + 9837936.

It is an arithmetic number, because the mean of its divisors is an integer number (2668902002256).

Almost surely, 2^{21006684280511} is an apocalyptic number.

21006684280511 is a deficient number, since it is larger than the sum of its proper divisors (344531737537).

21006684280511 is a wasteful number, since it uses less digits than its factorization.

21006684280511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2578513.

The product of its (nonzero) digits is 184320, while the sum is 44.

The spelling of 21006684280511 in words is "twenty-one trillion, six billion, six hundred eighty-four million, two hundred eighty thousand, five hundred eleven".