21665413551033 has 24 divisors (see below), whose sum is σ = 35823093366528. Its totient is φ = 12360171079872.

The previous prime is 21665413551031. The next prime is 21665413551077. The reversal of 21665413551033 is 33015531456612.

21665413551033 is a `hidden beast` number, since 2 + 1 + 6 + 6 + 54 + 13 + 551 + 0 + 33 = 666.

It is not a de Polignac number, because 21665413551033 - 2¹ = 21665413551031 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21665413551033.

It is not an unprimeable number, because it can be changed into a prime (21665413551031) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 278644641 + ... + 278722382.

It is an arithmetic number, because the mean of its divisors is an integer number (1492628890272).

Almost surely, 2^{21665413551033} is an apocalyptic number.

It is an amenable number.

21665413551033 is a deficient number, since it is larger than the sum of its proper divisors (14157679815495).

21665413551033 is a wasteful number, since it uses less digits than its factorization.

21665413551033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557367653 (or 557367650 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 45.

The spelling of 21665413551033 in words is "twenty-one trillion, six hundred sixty-five billion, four hundred thirteen million, five hundred fifty-one thousand, thirty-three".