2091907890 has 32 divisors (see below), whose sum is σ = 5578421760. Its totient is φ = 557842032.

The previous prime is 2091907793. The next prime is 2091907897. The reversal of 2091907890 is 987091902.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (2091907897) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3873634 + ... + 3874173.

It is an arithmetic number, because the mean of its divisors is an integer number (174325680).

Almost surely, 2^2091907890 is an apocalyptic number.

2091907890 is an abundant number, since it is smaller than the sum of its proper divisors (3486513870).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2091907890 is a wasteful number, since it uses less digits than its factorization.

2091907890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7747823 (or 7747817 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 2091907890 is about 45737.3795707625. The cubic root of 2091907890 is about 1278.9321925457.

The spelling of 2091907890 in words is "two billion, ninety-one million, nine hundred seven thousand, eight hundred ninety".