2990686721 has 4 divisors (see below), whose sum is σ = 3262567344. Its totient is φ = 2718806100.

The previous prime is 2990686717. The next prime is 2990686723. The reversal of 2990686721 is 1276860992.

It is a happy number.

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 2990686721 - 2² = 2990686717 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2990686721.

It is not an unprimeable number, because it can be changed into a prime (2990686723) 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, 135940295 + ... + 135940316.

It is an arithmetic number, because the mean of its divisors is an integer number (815641836).

Almost surely, 2^2990686721 is an apocalyptic number.

It is an amenable number.

2990686721 is a deficient number, since it is larger than the sum of its proper divisors (271880623).

2990686721 is a wasteful number, since it uses less digits than its factorization.

2990686721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271880622.

The product of its (nonzero) digits is 653184, while the sum is 50.

The square root of 2990686721 is about 54687.1714481559. The cubic root of 2990686721 is about 1440.7555707202.

The spelling of 2990686721 in words is "two billion, nine hundred ninety million, six hundred eighty-six thousand, seven hundred twenty-one".