20545403521 has 4 divisors (see below), whose sum is σ = 20805472000. Its totient is φ = 20285335044.

The previous prime is 20545403503. The next prime is 20545403563. The reversal of 20545403521 is 12530454502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20545403521 - 2⁷ = 20545403393 is a prime.

It is a super-2 number, since 2×20545403521² (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 (20545403581) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 130034121 + ... + 130034278.

It is an arithmetic number, because the mean of its divisors is an integer number (5201368000).

Almost surely, 2^20545403521 is an apocalyptic number.

It is an amenable number.

20545403521 is a deficient number, since it is larger than the sum of its proper divisors (260068479).

20545403521 is an equidigital number, since it uses as much as digits as its factorization.

20545403521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260068478.

The product of its (nonzero) digits is 24000, while the sum is 31.

The spelling of 20545403521 in words is "twenty billion, five hundred forty-five million, four hundred three thousand, five hundred twenty-one".