21255520067 has 2 divisors, whose sum is σ = 21255520068. Its totient is φ = 21255520066.

The previous prime is 21255520057. The next prime is 21255520151. The reversal of 21255520067 is 76002555212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21255520067 - 2¹² = 21255515971 is a prime.

It is not a weakly prime, because it can be changed into another prime (21255520037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10627760033 + 10627760034.

It is an arithmetic number, because the mean of its divisors is an integer number (10627760034).

Almost surely, 2^21255520067 is an apocalyptic number.

21255520067 is a deficient number, since it is larger than the sum of its proper divisors (1).

21255520067 is an equidigital number, since it uses as much as digits as its factorization.

21255520067 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42000, while the sum is 35.

The spelling of 21255520067 in words is "twenty-one billion, two hundred fifty-five million, five hundred twenty thousand, sixty-seven".