20427551 has 2 divisors, whose sum is σ = 20427552. Its totient is φ = 20427550.

The previous prime is 20427541. The next prime is 20427593. The reversal of 20427551 is 15572402.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20427551 - 2²² = 16233247 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20427551.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20427541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10213775 + 10213776.

It is an arithmetic number, because the mean of its divisors is an integer number (10213776).

Almost surely, 2^20427551 is an apocalyptic number.

20427551 is a deficient number, since it is larger than the sum of its proper divisors (1).

20427551 is an equidigital number, since it uses as much as digits as its factorization.

20427551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2800, while the sum is 26.

The square root of 20427551 is about 4519.6848341450. The cubic root of 20427551 is about 273.3623931361.

Adding to 20427551 its reverse (15572402), we get a palindrome (35999953).

The spelling of 20427551 in words is "twenty million, four hundred twenty-seven thousand, five hundred fifty-one".