2165777651 has 4 divisors (see below), whose sum is σ = 2195445912. Its totient is φ = 2136109392.

The previous prime is 2165777633. The next prime is 2165777683. The reversal of 2165777651 is 1567775612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2165777651 - 2¹⁸ = 2165515507 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2165777596 and 2165777605.

It is not an unprimeable number, because it can be changed into a prime (2165777051) 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, 14834021 + ... + 14834166.

It is an arithmetic number, because the mean of its divisors is an integer number (548861478).

Almost surely, 2^2165777651 is an apocalyptic number.

2165777651 is a deficient number, since it is larger than the sum of its proper divisors (29668261).

2165777651 is an equidigital number, since it uses as much as digits as its factorization.

2165777651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29668260.

The product of its digits is 617400, while the sum is 47.

The square root of 2165777651 is about 46537.9162726480. The cubic root of 2165777651 is about 1293.8123408515.

The spelling of 2165777651 in words is "two billion, one hundred sixty-five million, seven hundred seventy-seven thousand, six hundred fifty-one".