21121533659 has 8 divisors (see below), whose sum is σ = 21526464960. Its totient is φ = 20716839936.

The previous prime is 21121533541. The next prime is 21121533661. The reversal of 21121533659 is 95633512112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21121533659 is a prime.

It is a super-3 number, since 3×21121533659³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21121533689) 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 7 ways as a sum of consecutive naturals, for example, 125582 + ... + 240860.

It is an arithmetic number, because the mean of its divisors is an integer number (2690808120).

Almost surely, 2^21121533659 is an apocalyptic number.

21121533659 is a deficient number, since it is larger than the sum of its proper divisors (404931301).

21121533659 is a wasteful number, since it uses less digits than its factorization.

21121533659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118789.

The product of its digits is 48600, while the sum is 38.

The spelling of 21121533659 in words is "twenty-one billion, one hundred twenty-one million, five hundred thirty-three thousand, six hundred fifty-nine".