20454521 has 4 divisors (see below), whose sum is σ = 21343872. Its totient is φ = 19565172.

The previous prime is 20454481. The next prime is 20454523. The reversal of 20454521 is 12545402.

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 a de Polignac number, because none of the positive numbers 2^k-20454521 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 889327 = 20454521 / (2 + 0 + 4 + 5 + 4 + 5 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20454523) 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, 444641 + ... + 444686.

It is an arithmetic number, because the mean of its divisors is an integer number (5335968).

Almost surely, 2^20454521 is an apocalyptic number.

It is an amenable number.

20454521 is a deficient number, since it is larger than the sum of its proper divisors (889351).

20454521 is an equidigital number, since it uses as much as digits as its factorization.

20454521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 889350.

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 20454521 is about 4522.6674651139. The cubic root of 20454521 is about 273.4826448084.

Adding to 20454521 its reverse (12545402), we get a palindrome (32999923).

The spelling of 20454521 in words is "twenty million, four hundred fifty-four thousand, five hundred twenty-one".