2154165391 has 12 divisors (see below), whose sum is σ = 2507974920. Its totient is φ = 1844873520.

The previous prime is 2154165373. The next prime is 2154165397. The reversal of 2154165391 is 1935614512.

It is not a de Polignac number, because 2154165391 - 2⁹ = 2154164879 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 2154165391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2154165397) 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, 42336 + ... + 78106.

It is an arithmetic number, because the mean of its divisors is an integer number (208997910).

Almost surely, 2^2154165391 is an apocalyptic number.

2154165391 is a deficient number, since it is larger than the sum of its proper divisors (353809529).

2154165391 is a wasteful number, since it uses less digits than its factorization.

2154165391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37014 (or 37007 counting only the distinct ones).

The product of its digits is 32400, while the sum is 37.

The square root of 2154165391 is about 46412.9873095883. The cubic root of 2154165391 is about 1291.4958492631.

The spelling of 2154165391 in words is "two billion, one hundred fifty-four million, one hundred sixty-five thousand, three hundred ninety-one".