20616405149 has 2 divisors, whose sum is σ = 20616405150. Its totient is φ = 20616405148.

The previous prime is 20616405071. The next prime is 20616405151. The reversal of 20616405149 is 94150461602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12851623225 + 7764781924 = 113365^2 + 88118^2 .

It is a cyclic number.

It is not a de Polignac number, because 20616405149 - 2¹² = 20616401053 is a prime.

It is a super-2 number, since 2×20616405149² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 20616405151, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20616405949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10308202574 + 10308202575.

It is an arithmetic number, because the mean of its divisors is an integer number (10308202575).

Almost surely, 2^20616405149 is an apocalyptic number.

It is an amenable number.

20616405149 is a deficient number, since it is larger than the sum of its proper divisors (1).

20616405149 is an equidigital number, since it uses as much as digits as its factorization.

20616405149 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 38.

The spelling of 20616405149 in words is "twenty billion, six hundred sixteen million, four hundred five thousand, one hundred forty-nine".