2154378009 has 16 divisors (see below), whose sum is σ = 3303007232. Its totient is φ = 1223518608.

The previous prime is 2154378001. The next prime is 2154378059. The reversal of 2154378009 is 9008734512.

It is not a de Polignac number, because 2154378009 - 2³ = 2154378001 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2154378001) 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, 311269 + ... + 318114.

It is an arithmetic number, because the mean of its divisors is an integer number (206437952).

Almost surely, 2^2154378009 is an apocalyptic number.

It is an amenable number.

2154378009 is a deficient number, since it is larger than the sum of its proper divisors (1148629223).

2154378009 is a wasteful number, since it uses less digits than its factorization.

2154378009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 629556.

The product of its (nonzero) digits is 60480, while the sum is 39.

The square root of 2154378009 is about 46415.2777542050. The cubic root of 2154378009 is about 1291.5383384536.

It can be divided in two parts, 215437 and 8009, that added together give a triangular number (223446 = T₆₆₈).

The spelling of 2154378009 in words is "two billion, one hundred fifty-four million, three hundred seventy-eight thousand, nine".