21145985267 has 48 divisors (see below), whose sum is σ = 25319116800. Its totient is φ = 17464507200.

The previous prime is 21145985251. The next prime is 21145985293. The reversal of 21145985267 is 76258954112.

It is not a de Polignac number, because 21145985267 - 2⁴ = 21145985251 is a prime.

It is a super-2 number, since 2×21145985267² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21145985207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 25507409 + ... + 25508237.

It is an arithmetic number, because the mean of its divisors is an integer number (527481600).

Almost surely, 2^21145985267 is an apocalyptic number.

21145985267 is a deficient number, since it is larger than the sum of its proper divisors (4173131533).

21145985267 is a wasteful number, since it uses less digits than its factorization.

21145985267 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1048 (or 1017 counting only the distinct ones).

The product of its digits is 1209600, while the sum is 50.

The spelling of 21145985267 in words is "twenty-one billion, one hundred forty-five million, nine hundred eighty-five thousand, two hundred sixty-seven".