21666706628253 has 8 divisors (see below), whose sum is σ = 28916962487616. Its totient is φ = 14430460927200.

The previous prime is 21666706628219. The next prime is 21666706628263. The reversal of 21666706628253 is 35282660766612.

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

It is a de Polignac number, because none of the positive numbers 2^k-21666706628253 is a prime.

It is a super-2 number, since 2×21666706628253² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21666706628263) 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, 3502535968 + ... + 3502542153.

It is an arithmetic number, because the mean of its divisors is an integer number (3614620310952).

Almost surely, 2^{21666706628253} is an apocalyptic number.

It is an amenable number.

21666706628253 is a deficient number, since it is larger than the sum of its proper divisors (7250255859363).

21666706628253 is a wasteful number, since it uses less digits than its factorization.

21666706628253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7005079155.

The product of its (nonzero) digits is 52254720, while the sum is 60.

The spelling of 21666706628253 in words is "twenty-one trillion, six hundred sixty-six billion, seven hundred six million, six hundred twenty-eight thousand, two hundred fifty-three".