21755046506641 has 16 divisors (see below), whose sum is σ = 25556199041664. Its totient is φ = 18133443304704.

The previous prime is 21755046506593. The next prime is 21755046506651. The reversal of 21755046506641 is 14660564055712.

It is a de Polignac number, because none of the positive numbers 2^k-21755046506641 is a prime.

It is a super-2 number, since 2×21755046506641² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21755046506651) 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, 259422411 + ... + 259506256.

It is an arithmetic number, because the mean of its divisors is an integer number (1597262440104).

Almost surely, 2^{21755046506641} is an apocalyptic number.

It is an amenable number.

21755046506641 is a deficient number, since it is larger than the sum of its proper divisors (3801152535023).

21755046506641 is a wasteful number, since it uses less digits than its factorization.

21755046506641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 518928840.

The product of its (nonzero) digits is 6048000, while the sum is 52.

The spelling of 21755046506641 in words is "twenty-one trillion, seven hundred fifty-five billion, forty-six million, five hundred six thousand, six hundred forty-one".