2161977747 has 8 divisors (see below), whose sum is σ = 2960546256. Its totient is φ = 1402363872.

The previous prime is 2161977743. The next prime is 2161977781. The reversal of 2161977747 is 7477791612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2161977747 - 2² = 2161977743 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2161977747.

It is not an unprimeable number, because it can be changed into a prime (2161977743) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9738528 + ... + 9738749.

It is an arithmetic number, because the mean of its divisors is an integer number (370068282).

Almost surely, 2^2161977747 is an apocalyptic number.

2161977747 is a deficient number, since it is larger than the sum of its proper divisors (798568509).

2161977747 is a wasteful number, since it uses less digits than its factorization.

2161977747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19477317.

The product of its digits is 1037232, while the sum is 51.

The square root of 2161977747 is about 46497.0724562310. The cubic root of 2161977747 is about 1293.0552239208.

The spelling of 2161977747 in words is "two billion, one hundred sixty-one million, nine hundred seventy-seven thousand, seven hundred forty-seven".