1978919826 has 32 divisors (see below), whose sum is σ = 4334541120. Its totient is φ = 598576704.

The previous prime is 1978919801. The next prime is 1978919827. The reversal of 1978919826 is 6289198791.

It is a super-2 number, since 2×1978919826² = 7832247355471740552, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1978919826.

It is not an unprimeable number, because it can be changed into a prime (1978919827) 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, 210405 + ... + 219608.

It is an arithmetic number, because the mean of its divisors is an integer number (135454410).

Almost surely, 2^1978919826 is an apocalyptic number.

1978919826 is an abundant number, since it is smaller than the sum of its proper divisors (2355621294).

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

1978919826 is a wasteful number, since it uses less digits than its factorization.

1978919826 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430090.

The product of its digits is 3919104, while the sum is 60.

The square root of 1978919826 is about 44485.0517140309. The cubic root of 1978919826 is about 1255.4788469171.

The spelling of 1978919826 in words is "one billion, nine hundred seventy-eight million, nine hundred nineteen thousand, eight hundred twenty-six".