2178261349 has 4 divisors (see below), whose sum is σ = 2376285120. Its totient is φ = 1980237580.

The previous prime is 2178261347. The next prime is 2178261359. The reversal of 2178261349 is 9431628712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2178261349 - 2¹ = 2178261347 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2178261343) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99011869 + ... + 99011890.

It is an arithmetic number, because the mean of its divisors is an integer number (594071280).

Almost surely, 2^2178261349 is an apocalyptic number.

It is an amenable number.

2178261349 is a deficient number, since it is larger than the sum of its proper divisors (198023771).

2178261349 is a wasteful number, since it uses less digits than its factorization.

2178261349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198023770.

The product of its digits is 145152, while the sum is 43.

The square root of 2178261349 is about 46671.8474993223. The cubic root of 2178261349 is about 1296.2934555984.

The spelling of 2178261349 in words is "two billion, one hundred seventy-eight million, two hundred sixty-one thousand, three hundred forty-nine".