1620225531 has 8 divisors (see below), whose sum is σ = 2400334160. Its totient is φ = 1080150336.

The previous prime is 1620225521. The next prime is 1620225533. The reversal of 1620225531 is 1355220261.

It is a happy number.

1620225531 is a `hidden beast` number, since 1 + 620 + 2 + 2 + 5 + 5 + 31 = 666.

It is not a de Polignac number, because 1620225531 - 2⁵ = 1620225499 is a prime.

It is a super-2 number, since 2×1620225531² = 5250261542608463922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 60008353 = 1620225531 / (1 + 6 + 2 + 0 + 2 + 2 + 5 + 5 + 3 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1620225495 and 1620225504.

It is not an unprimeable number, because it can be changed into a prime (1620225533) 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 in 7 ways as a sum of consecutive naturals, for example, 30004150 + ... + 30004203.

It is an arithmetic number, because the mean of its divisors is an integer number (300041770).

Almost surely, 2^1620225531 is an apocalyptic number.

1620225531 is a deficient number, since it is larger than the sum of its proper divisors (780108629).

1620225531 is an equidigital number, since it uses as much as digits as its factorization.

1620225531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60008362 (or 60008356 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 1620225531 is about 40252.0251788652. The cubic root of 1620225531 is about 1174.5147913040.

Adding to 1620225531 its reverse (1355220261), we get a palindrome (2975445792).

The spelling of 1620225531 in words is "one billion, six hundred twenty million, two hundred twenty-five thousand, five hundred thirty-one".