1645915120 has 20 divisors (see below), whose sum is σ = 3826752840. Its totient is φ = 658366016.

The previous prime is 1645915079. The next prime is 1645915133. The reversal of 1645915120 is 215195461.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×1645915120² = 5418073164489228800, which contains 22 as substring.

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, 10286890 + ... + 10287049.

It is an arithmetic number, because the mean of its divisors is an integer number (191337642).

Almost surely, 2^1645915120 is an apocalyptic number.

1645915120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1645915120 is an abundant number, since it is smaller than the sum of its proper divisors (2180837720).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1645915120 is a wasteful number, since it uses less digits than its factorization.

1645915120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20573952 (or 20573946 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 34.

The square root of 1645915120 is about 40569.8794674078. The cubic root of 1645915120 is about 1180.6898006443.

The spelling of 1645915120 in words is "one billion, six hundred forty-five million, nine hundred fifteen thousand, one hundred twenty".