2009778771 has 64 divisors (see below), whose sum is σ = 3614155776. Its totient is φ = 959385600.

The previous prime is 2009778767. The next prime is 2009778779. The reversal of 2009778771 is 1778779002.

It is not a de Polignac number, because 2009778771 - 2² = 2009778767 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2009778771.

It is not an unprimeable number, because it can be changed into a prime (2009778779) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 722335 + ... + 725111.

It is an arithmetic number, because the mean of its divisors is an integer number (56471184).

Almost surely, 2^2009778771 is an apocalyptic number.

2009778771 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

2009778771 is a deficient number, since it is larger than the sum of its proper divisors (1604377005).

2009778771 is a wasteful number, since it uses less digits than its factorization.

2009778771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3052.

The product of its (nonzero) digits is 345744, while the sum is 48.

The square root of 2009778771 is about 44830.5562200604. The cubic root of 2009778771 is about 1261.9711255504.

The spelling of 2009778771 in words is "two billion, nine million, seven hundred seventy-eight thousand, seven hundred seventy-one".