1620123505 has 96 divisors (see below), whose sum is σ = 2684803968. Its totient is φ = 922521600.

The previous prime is 1620123499. The next prime is 1620123517. The reversal of 1620123505 is 5053210261.

It is not a de Polignac number, because 1620123505 - 2⁷ = 1620123377 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1620123505.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4589409 + ... + 4589761.

It is an arithmetic number, because the mean of its divisors is an integer number (27966708).

Almost surely, 2^1620123505 is an apocalyptic number.

It is an amenable number.

1620123505 is a deficient number, since it is larger than the sum of its proper divisors (1064680463).

1620123505 is a wasteful number, since it uses less digits than its factorization.

1620123505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 527 (or 520 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 1620123505 is about 40250.7578189529. The cubic root of 1620123505 is about 1174.4901376248.

Adding to 1620123505 its reverse (5053210261), we get a palindrome (6673333766).

The spelling of 1620123505 in words is "one billion, six hundred twenty million, one hundred twenty-three thousand, five hundred five".