2151722665 has 8 divisors (see below), whose sum is σ = 2591886528. Its totient is φ = 1714831920.

The previous prime is 2151722603. The next prime is 2151722687. The reversal of 2151722665 is 5662271512.

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

It is not a de Polignac number, because 2151722665 - 2²³ = 2143334057 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 816831 + ... + 819460.

It is an arithmetic number, because the mean of its divisors is an integer number (323985816).

Almost surely, 2^2151722665 is an apocalyptic number.

It is an amenable number.

2151722665 is a deficient number, since it is larger than the sum of its proper divisors (440163863).

2151722665 is a wasteful number, since it uses less digits than its factorization.

2151722665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1636559.

The product of its digits is 50400, while the sum is 37.

The square root of 2151722665 is about 46386.6647324422. The cubic root of 2151722665 is about 1291.0074986920.

The spelling of 2151722665 in words is "two billion, one hundred fifty-one million, seven hundred twenty-two thousand, six hundred sixty-five".