1608621381 has 12 divisors (see below), whose sum is σ = 2324275200. Its totient is φ = 1072086120.

The previous prime is 1608621373. The next prime is 1608621383. The reversal of 1608621381 is 1831268061.

It is not a de Polignac number, because 1608621381 - 2³ = 1608621373 is a prime.

It is a super-2 number, since 2×1608621381² = 5175325494820694322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1608621383) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5820 + ... + 57018.

It is an arithmetic number, because the mean of its divisors is an integer number (193689600).

Almost surely, 2^1608621381 is an apocalyptic number.

It is an amenable number.

1608621381 is a deficient number, since it is larger than the sum of its proper divisors (715653819).

1608621381 is a wasteful number, since it uses less digits than its factorization.

1608621381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54696 (or 54693 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 1608621381 is about 40107.6224800224. The cubic root of 1608621381 is about 1171.7040892424.

The spelling of 1608621381 in words is "one billion, six hundred eight million, six hundred twenty-one thousand, three hundred eighty-one".