20145827521 has 4 divisors (see below), whose sum is σ = 20200721152. Its totient is φ = 20090933892.

The previous prime is 20145827519. The next prime is 20145827551. The reversal of 20145827521 is 12572854102.

It is a happy number.

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 20145827521 - 2¹ = 20145827519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20145827551) 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, 27446265 + ... + 27446998.

It is an arithmetic number, because the mean of its divisors is an integer number (5050180288).

Almost surely, 2^20145827521 is an apocalyptic number.

It is an amenable number.

20145827521 is a deficient number, since it is larger than the sum of its proper divisors (54893631).

20145827521 is an equidigital number, since it uses as much as digits as its factorization.

20145827521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54893630.

The product of its (nonzero) digits is 44800, while the sum is 37.

The spelling of 20145827521 in words is "twenty billion, one hundred forty-five million, eight hundred twenty-seven thousand, five hundred twenty-one".