1620856064 has 18 divisors (see below), whose sum is σ = 3235381170. Its totient is φ = 810427904.

The previous prime is 1620856063. The next prime is 1620856073. The reversal of 1620856064 is 4606580261.

It can be written as a sum of positive squares in only one way, i.e., 1462297600 + 158558464 = 38240^2 + 12592^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620856063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3165479 + ... + 3165990.

Almost surely, 2^1620856064 is an apocalyptic number.

It is an amenable number.

1620856064 is a deficient number, since it is larger than the sum of its proper divisors (1614525106).

1620856064 is an frugal number, since it uses more digits than its factorization.

1620856064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6331485 (or 6331471 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 1620856064 is about 40259.8567309920. The cubic root of 1620856064 is about 1174.6671310604.

The spelling of 1620856064 in words is "one billion, six hundred twenty million, eight hundred fifty-six thousand, sixty-four".