1620631233 has 40 divisors (see below), whose sum is σ = 2760562728. Its totient is φ = 938635776.

The previous prime is 1620631217. The next prime is 1620631247. The reversal of 1620631233 is 3321360261.

It is a happy number.

1620631233 is a `hidden beast` number, since 1 + 6 + 2 + 0 + 631 + 23 + 3 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 5184 + 1620626049 = 72^2 + 40257^2 .

It is not a de Polignac number, because 1620631233 - 2⁴ = 1620631217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1620631197 and 1620631206.

It is not an unprimeable number, because it can be changed into a prime (1620631253) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 27366 + ... + 63167.

Almost surely, 2^1620631233 is an apocalyptic number.

1620631233 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1620631233 is a deficient number, since it is larger than the sum of its proper divisors (1139931495).

1620631233 is a wasteful number, since it uses less digits than its factorization.

1620631233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90575 (or 90566 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 1620631233 is about 40257.0643862664. The cubic root of 1620631233 is about 1174.6128153598.

Adding to 1620631233 its reverse (3321360261), we get a palindrome (4941991494).

The spelling of 1620631233 in words is "one billion, six hundred twenty million, six hundred thirty-one thousand, two hundred thirty-three".