21254016355291 has 2 divisors, whose sum is σ = 21254016355292. Its totient is φ = 21254016355290.

The previous prime is 21254016355219. The next prime is 21254016355367. The reversal of 21254016355291 is 19255361045212.

Together with previous prime (21254016355219) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21254016355291 - 2¹⁹ = 21254015831003 is a prime.

It is a super-2 number, since 2×21254016355291² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21254016355211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10627008177645 + 10627008177646.

It is an arithmetic number, because the mean of its divisors is an integer number (10627008177646).

Almost surely, 2^{21254016355291} is an apocalyptic number.

21254016355291 is a deficient number, since it is larger than the sum of its proper divisors (1).

21254016355291 is an equidigital number, since it uses as much as digits as its factorization.

21254016355291 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648000, while the sum is 46.

The spelling of 21254016355291 in words is "twenty-one trillion, two hundred fifty-four billion, sixteen million, three hundred fifty-five thousand, two hundred ninety-one".