21266021516601 has 8 divisors (see below), whose sum is σ = 30022618611744. Its totient is φ = 13343386049600.

The previous prime is 21266021516563. The next prime is 21266021516659. The reversal of 21266021516601 is 10661512066212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21266021516601 - 2¹⁰ = 21266021515577 is a prime.

It is a super-2 number, since 2×21266021516601² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21266021516601.

It is not an unprimeable number, because it can be changed into a prime (21266021514601) 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, 208490406975 + ... + 208490407076.

It is an arithmetic number, because the mean of its divisors is an integer number (3752827326468).

Almost surely, 2^{21266021516601} is an apocalyptic number.

It is an amenable number.

21266021516601 is a deficient number, since it is larger than the sum of its proper divisors (8756597095143).

21266021516601 is a wasteful number, since it uses less digits than its factorization.

21266021516601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 416980814071.

The product of its (nonzero) digits is 51840, while the sum is 39.

The spelling of 21266021516601 in words is "twenty-one trillion, two hundred sixty-six billion, twenty-one million, five hundred sixteen thousand, six hundred one".