21354776465553 has 12 divisors (see below), whose sum is σ = 30845906859508. Its totient is φ = 14236462890720.

The previous prime is 21354776465521. The next prime is 21354776465591. The reversal of 21354776465553 is 35556467745312.

21354776465553 is a `hidden beast` number, since 2 + 1 + 3 + 5 + 4 + 7 + 76 + 4 + 6 + 5 + 553 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 8039079196929 + 13315697268624 = 2835327^2 + 3649068^2 .

It is not a de Polignac number, because 21354776465553 - 2⁵ = 21354776465521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21354776465753) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2017918 + ... + 6839703.

Almost surely, 2^{21354776465553} is an apocalyptic number.

It is an amenable number.

21354776465553 is a deficient number, since it is larger than the sum of its proper divisors (9491130393955).

21354776465553 is a wasteful number, since it uses less digits than its factorization.

21354776465553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9125504 (or 9125501 counting only the distinct ones).

The product of its digits is 317520000, while the sum is 63.

The spelling of 21354776465553 in words is "twenty-one trillion, three hundred fifty-four billion, seven hundred seventy-six million, four hundred sixty-five thousand, five hundred fifty-three".