2986857721 has 4 divisors (see below), whose sum is σ = 3162555252. Its totient is φ = 2811160192.

The previous prime is 2986857691. The next prime is 2986857733. The reversal of 2986857721 is 1277586892.

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

It can be written as a sum of positive squares in 2 ways, for example, as 2616834025 + 370023696 = 51155^2 + 19236^2 .

It is a cyclic number.

It is not a de Polignac number, because 2986857721 - 2⁷ = 2986857593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2986857751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87848740 + ... + 87848773.

It is an arithmetic number, because the mean of its divisors is an integer number (790638813).

Almost surely, 2^2986857721 is an apocalyptic number.

It is an amenable number.

2986857721 is a deficient number, since it is larger than the sum of its proper divisors (175697531).

2986857721 is a wasteful number, since it uses less digits than its factorization.

2986857721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175697530.

The product of its digits is 3386880, while the sum is 55.

The square root of 2986857721 is about 54652.1520253320. The cubic root of 2986857721 is about 1440.1404378528.

The spelling of 2986857721 in words is "two billion, nine hundred eighty-six million, eight hundred fifty-seven thousand, seven hundred twenty-one".