21530120667 has 48 divisors (see below), whose sum is σ = 32047166592. Its totient is φ = 12749917440.

The previous prime is 21530120659. The next prime is 21530120671. The reversal of 21530120667 is 76602103512.

It is not a de Polignac number, because 21530120667 - 2³ = 21530120659 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21530120627) 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, 22036483 + ... + 22037459.

It is an arithmetic number, because the mean of its divisors is an integer number (667649304).

Almost surely, 2^21530120667 is an apocalyptic number.

21530120667 is a deficient number, since it is larger than the sum of its proper divisors (10517045925).

21530120667 is a wasteful number, since it uses less digits than its factorization.

21530120667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1256 (or 1177 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 33.

The spelling of 21530120667 in words is "twenty-one billion, five hundred thirty million, one hundred twenty thousand, six hundred sixty-seven".