2190168778 has 24 divisors (see below), whose sum is σ = 3838062852. Its totient is φ = 934605504.

The previous prime is 2190168749. The next prime is 2190168781. The reversal of 2190168778 is 8778610912.

It can be written as a sum of positive squares in 2 ways, for example, as 2161041169 + 29127609 = 46487^2 + 5397^2 .

It is a super-2 number, since 2×2190168778² = 9593678552252026568, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25125 + ... + 70792.

Almost surely, 2^2190168778 is an apocalyptic number.

2190168778 is a deficient number, since it is larger than the sum of its proper divisors (1647894074).

2190168778 is a wasteful number, since it uses less digits than its factorization.

2190168778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96166 (or 96159 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 49.

The square root of 2190168778 is about 46799.2390750106. The cubic root of 2190168778 is about 1298.6512200286.

The spelling of 2190168778 in words is "two billion, one hundred ninety million, one hundred sixty-eight thousand, seven hundred seventy-eight".