21129648267 has 96 divisors (see below), whose sum is σ = 36681705984. Its totient is φ = 10529326080.

The previous prime is 21129648251. The next prime is 21129648341. The reversal of 21129648267 is 76284692112.

It is not a de Polignac number, because 21129648267 - 2⁴ = 21129648251 is a prime.

It is a super-2 number, since 2×21129648267² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21129648217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 11280243 + ... + 11282115.

It is an arithmetic number, because the mean of its divisors is an integer number (382101104).

Almost surely, 2^21129648267 is an apocalyptic number.

21129648267 is a deficient number, since it is larger than the sum of its proper divisors (15552057717).

21129648267 is a wasteful number, since it uses less digits than its factorization.

21129648267 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2001 (or 1970 counting only the distinct ones).

The product of its digits is 580608, while the sum is 48.

The spelling of 21129648267 in words is "twenty-one billion, one hundred twenty-nine million, six hundred forty-eight thousand, two hundred sixty-seven".