2091779478 has 28 divisors (see below), whose sum is σ = 4704355068. Its totient is φ = 697259340.

The previous prime is 2091779477. The next prime is 2091779491. The reversal of 2091779478 is 8749771902.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2091779477) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 715888 + ... + 718803.

It is an arithmetic number, because the mean of its divisors is an integer number (168012681).

Almost surely, 2^2091779478 is an apocalyptic number.

2091779478 is an abundant number, since it is smaller than the sum of its proper divisors (2612575590).

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

2091779478 is an equidigital number, since it uses as much as digits as its factorization.

2091779478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1434711 (or 1434696 counting only the distinct ones).

The product of its (nonzero) digits is 1778112, while the sum is 54.

The square root of 2091779478 is about 45735.9757521363. The cubic root of 2091779478 is about 1278.9060228783.

The spelling of 2091779478 in words is "two billion, ninety-one million, seven hundred seventy-nine thousand, four hundred seventy-eight".