1620173231 has 2 divisors, whose sum is σ = 1620173232. Its totient is φ = 1620173230.

The previous prime is 1620173209. The next prime is 1620173251. The reversal of 1620173231 is 1323710261.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1620173231 - 2²⁶ = 1553064367 is a prime.

It is a super-2 number, since 2×1620173231² = 5249922596897958722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1620173231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1620173201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810086615 + 810086616.

It is an arithmetic number, because the mean of its divisors is an integer number (810086616).

Almost surely, 2^1620173231 is an apocalyptic number.

1620173231 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620173231 is an equidigital number, since it uses as much as digits as its factorization.

1620173231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 1620173231 is about 40251.3755168690. The cubic root of 1620173231 is about 1174.5021536016.

Adding to 1620173231 its reverse (1323710261), we get a palindrome (2943883492).

The spelling of 1620173231 in words is "one billion, six hundred twenty million, one hundred seventy-three thousand, two hundred thirty-one".