20545540521 has 16 divisors (see below), whose sum is σ = 29888256960. Its totient is φ = 12450245120.

The previous prime is 20545540517. The next prime is 20545540549. The reversal of 20545540521 is 12504554502.

It is a cyclic number.

It is not a de Polignac number, because 20545540521 - 2² = 20545540517 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 (20545540511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 253285 + ... + 324413.

It is an arithmetic number, because the mean of its divisors is an integer number (1868016060).

Almost surely, 2^20545540521 is an apocalyptic number.

It is an amenable number.

20545540521 is a deficient number, since it is larger than the sum of its proper divisors (9342716439).

20545540521 is a wasteful number, since it uses less digits than its factorization.

20545540521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79896.

The product of its (nonzero) digits is 40000, while the sum is 33.

The spelling of 20545540521 in words is "twenty billion, five hundred forty-five million, five hundred forty thousand, five hundred twenty-one".