2154563909 has 16 divisors (see below), whose sum is σ = 2234712816. Its totient is φ = 2075673600.

The previous prime is 2154563863. The next prime is 2154563911. The reversal of 2154563909 is 9093654512.

It can be written as a sum of positive squares in 8 ways, for example, as 348568900 + 1805995009 = 18670^2 + 42497^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2154563909 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 2154563909.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2154563959) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2445149 + ... + 2446029.

It is an arithmetic number, because the mean of its divisors is an integer number (139669551).

Almost surely, 2^2154563909 is an apocalyptic number.

It is an amenable number.

2154563909 is a deficient number, since it is larger than the sum of its proper divisors (80148907).

2154563909 is a wasteful number, since it uses less digits than its factorization.

2154563909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1496.

The product of its (nonzero) digits is 291600, while the sum is 44.

The square root of 2154563909 is about 46417.2802843941. The cubic root of 2154563909 is about 1291.5754860774.

The spelling of 2154563909 in words is "two billion, one hundred fifty-four million, five hundred sixty-three thousand, nine hundred nine".