21266350605 has 16 divisors (see below), whose sum is σ = 37806845760. Its totient is φ = 11342053584.

The previous prime is 21266350601. The next prime is 21266350607. The reversal of 21266350605 is 50605366212.

It is a happy number.

21266350605 is a `hidden beast` number, since 2 + 12 + 6 + 6 + 35 + 0 + 605 = 666.

It is not a de Polignac number, because 21266350605 - 2² = 21266350601 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21266350605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21266350601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78764127 + ... + 78764396.

It is an arithmetic number, because the mean of its divisors is an integer number (2362927860).

Almost surely, 2^21266350605 is an apocalyptic number.

It is an amenable number.

21266350605 is a deficient number, since it is larger than the sum of its proper divisors (16540495155).

21266350605 is a wasteful number, since it uses less digits than its factorization.

21266350605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157528537 (or 157528531 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The spelling of 21266350605 in words is "twenty-one billion, two hundred sixty-six million, three hundred fifty thousand, six hundred five".