1620226631 has 2 divisors, whose sum is σ = 1620226632. Its totient is φ = 1620226630.

The previous prime is 1620226613. The next prime is 1620226669. The reversal of 1620226631 is 1366220261.

Together with previous prime (1620226613) 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 a de Polignac number, because none of the positive numbers 2^k-1620226631 is a prime.

It is a super-2 number, since 2×1620226631² = 5250268671603220322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1620226594 and 1620226603.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1620226331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810113315 + 810113316.

It is an arithmetic number, because the mean of its divisors is an integer number (810113316).

Almost surely, 2^1620226631 is an apocalyptic number.

1620226631 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620226631 is an equidigital number, since it uses as much as digits as its factorization.

1620226631 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 1620226631 is about 40252.0388427717. The cubic root of 1620226631 is about 1174.5150571036.

Adding to 1620226631 its reverse (1366220261), we get a palindrome (2986446892).

The spelling of 1620226631 in words is "one billion, six hundred twenty million, two hundred twenty-six thousand, six hundred thirty-one".