20253561 has 8 divisors (see below), whose sum is σ = 27032160. Its totient is φ = 13488672.

The previous prime is 20253553. The next prime is 20253581. The reversal of 20253561 is 16535202.

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

It is not a de Polignac number, because 20253561 - 2³ = 20253553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20253521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 750 + ... + 6408.

It is an arithmetic number, because the mean of its divisors is an integer number (3379020).

Almost surely, 2^20253561 is an apocalyptic number.

It is an amenable number.

20253561 is a deficient number, since it is larger than the sum of its proper divisors (6778599).

20253561 is a wasteful number, since it uses less digits than its factorization.

20253561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6855.

The product of its (nonzero) digits is 1800, while the sum is 24.

The square root of 20253561 is about 4500.3956492735. The cubic root of 20253561 is about 272.5840651894.

Adding to 20253561 its reverse (16535202), we get a palindrome (36788763).

The spelling of 20253561 in words is "twenty million, two hundred fifty-three thousand, five hundred sixty-one".