21355466727551 has 16 divisors (see below), whose sum is σ = 24533832393600. Its totient is φ = 18384161695200.

The previous prime is 21355466727461. The next prime is 21355466727563. The reversal of 21355466727551 is 15572766455312.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21355466727551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21355466727251) 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, 22042145 + ... + 22990586.

It is an arithmetic number, because the mean of its divisors is an integer number (1533364524600).

Almost surely, 2^{21355466727551} is an apocalyptic number.

21355466727551 is a deficient number, since it is larger than the sum of its proper divisors (3178365666049).

21355466727551 is a wasteful number, since it uses less digits than its factorization.

21355466727551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45035030.

The product of its digits is 52920000, while the sum is 59.

The spelling of 21355466727551 in words is "twenty-one trillion, three hundred fifty-five billion, four hundred sixty-six million, seven hundred twenty-seven thousand, five hundred fifty-one".