20616331 has 2 divisors, whose sum is σ = 20616332. Its totient is φ = 20616330.

The previous prime is 20616313. The next prime is 20616373. The reversal of 20616331 is 13361602.

Together with previous prime (20616313) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20616331 - 2¹³ = 20608139 is a prime.

It is a super-2 number, since 2×20616331² = 850066207803122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20616301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10308165 + 10308166.

It is an arithmetic number, because the mean of its divisors is an integer number (10308166).

Almost surely, 2^20616331 is an apocalyptic number.

20616331 is a deficient number, since it is larger than the sum of its proper divisors (1).

20616331 is an equidigital number, since it uses as much as digits as its factorization.

20616331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 22.

The square root of 20616331 is about 4540.5210053473. The cubic root of 20616331 is about 274.2018997822.

Adding to 20616331 its reverse (13361602), we get a palindrome (33977933).

The spelling of 20616331 in words is "twenty million, six hundred sixteen thousand, three hundred thirty-one".