20121534521 has 8 divisors (see below), whose sum is σ = 22905146304. Its totient is φ = 17496986320.

The previous prime is 20121534497. The next prime is 20121534523. The reversal of 20121534521 is 12543512102.

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

It is not a de Polignac number, because 20121534521 - 2³⁰ = 19047792697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20121534523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39765626 + ... + 39766131.

It is an arithmetic number, because the mean of its divisors is an integer number (2863143288).

Almost surely, 2^20121534521 is an apocalyptic number.

It is an amenable number.

20121534521 is a deficient number, since it is larger than the sum of its proper divisors (2783611783).

20121534521 is a wasteful number, since it uses less digits than its factorization.

20121534521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79531791.

The product of its (nonzero) digits is 2400, while the sum is 26.

The spelling of 20121534521 in words is "twenty billion, one hundred twenty-one million, five hundred thirty-four thousand, five hundred twenty-one".