1620604889 has 4 divisors (see below), whose sum is σ = 1620689424. Its totient is φ = 1620520356.

The previous prime is 1620604871. The next prime is 1620604897. The reversal of 1620604889 is 9884060261.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1620604889 - 2²⁸ = 1352169433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1620604859) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1814 + ... + 56960.

It is an arithmetic number, because the mean of its divisors is an integer number (405172356).

Almost surely, 2^1620604889 is an apocalyptic number.

It is an amenable number.

1620604889 is a deficient number, since it is larger than the sum of its proper divisors (84535).

1620604889 is an equidigital number, since it uses as much as digits as its factorization.

1620604889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84534.

The product of its (nonzero) digits is 165888, while the sum is 44.

The square root of 1620604889 is about 40256.7371877056. The cubic root of 1620604889 is about 1174.6064507271.

The spelling of 1620604889 in words is "one billion, six hundred twenty million, six hundred four thousand, eight hundred eighty-nine".