20655619 has 2 divisors, whose sum is σ = 20655620. Its totient is φ = 20655618.

The previous prime is 20655563. The next prime is 20655623. The reversal of 20655619 is 91655602.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20655619 - 2¹³ = 20647427 is a prime.

It is a super-2 number, since 2×20655619² = 853309192546322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20655659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10327809 + 10327810.

It is an arithmetic number, because the mean of its divisors is an integer number (10327810).

Almost surely, 2^20655619 is an apocalyptic number.

20655619 is a deficient number, since it is larger than the sum of its proper divisors (1).

20655619 is an equidigital number, since it uses as much as digits as its factorization.

20655619 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16200, while the sum is 34.

The square root of 20655619 is about 4544.8453219004. The cubic root of 20655619 is about 274.3759690399.

The spelling of 20655619 in words is "twenty million, six hundred fifty-five thousand, six hundred nineteen".