1620513655 has 4 divisors (see below), whose sum is σ = 1944616392. Its totient is φ = 1296410920.

The previous prime is 1620513619. The next prime is 1620513673. The reversal of 1620513655 is 5563150261.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5563150261 = 17 ⋅327244133.

It is not a de Polignac number, because 1620513655 - 2⁷ = 1620513527 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1620513655.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 162051361 + ... + 162051370.

It is an arithmetic number, because the mean of its divisors is an integer number (486154098).

Almost surely, 2^1620513655 is an apocalyptic number.

1620513655 is a deficient number, since it is larger than the sum of its proper divisors (324102737).

1620513655 is an equidigital number, since it uses as much as digits as its factorization.

1620513655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324102736.

The product of its (nonzero) digits is 27000, while the sum is 34.

The square root of 1620513655 is about 40255.6040198132. The cubic root of 1620513655 is about 1174.5844083287.

The spelling of 1620513655 in words is "one billion, six hundred twenty million, five hundred thirteen thousand, six hundred fifty-five".