1620138020 has 24 divisors (see below), whose sum is σ = 3403378104. Its totient is φ = 647847936.

The previous prime is 1620138007. The next prime is 1620138043. The reversal of 1620138020 is 208310261.

It can be written as a sum of positive squares in 4 ways, for example, as 198697216 + 1421440804 = 14096^2 + 37702^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61604 + ... + 83876.

It is an arithmetic number, because the mean of its divisors is an integer number (141807421).

Almost surely, 2^1620138020 is an apocalyptic number.

1620138020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1620138020 is an abundant number, since it is smaller than the sum of its proper divisors (1783240084).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1620138020 is a wasteful number, since it uses less digits than its factorization.

1620138020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25919 (or 25917 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 1620138020 is about 40250.9381257133. The cubic root of 1620138020 is about 1174.4936451092.

Adding to 1620138020 its reverse (208310261), we get a palindrome (1828448281).

The spelling of 1620138020 in words is "one billion, six hundred twenty million, one hundred thirty-eight thousand, twenty".