20627561 has 4 divisors (see below), whose sum is σ = 20637072. Its totient is φ = 20618052.

The previous prime is 20627557. The next prime is 20627569. The reversal of 20627561 is 16572602.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20627561 - 2² = 20627557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20627569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266 + ... + 6428.

It is an arithmetic number, because the mean of its divisors is an integer number (5159268).

Almost surely, 2^20627561 is an apocalyptic number.

It is an amenable number.

20627561 is a deficient number, since it is larger than the sum of its proper divisors (9511).

20627561 is an equidigital number, since it uses as much as digits as its factorization.

20627561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9510.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 20627561 is about 4541.7574792144. The cubic root of 20627561 is about 274.2516779313.

The spelling of 20627561 in words is "twenty million, six hundred twenty-seven thousand, five hundred sixty-one".