1919779990 has 16 divisors (see below), whose sum is σ = 3574763280. Its totient is φ = 741432160.

The previous prime is 1919779987. The next prime is 1919779999. The reversal of 1919779990 is 999779191.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1919779999) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3309676 + ... + 3310255.

It is an arithmetic number, because the mean of its divisors is an integer number (223422705).

Almost surely, 2^1919779990 is an apocalyptic number.

1919779990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1919779990 is a deficient number, since it is larger than the sum of its proper divisors (1654983290).

1919779990 is a wasteful number, since it uses less digits than its factorization.

1919779990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6619967.

The product of its (nonzero) digits is 2893401, while the sum is 61.

The square root of 1919779990 is about 43815.2940193262. The cubic root of 1919779990 is about 1242.8455268026.

The spelling of 1919779990 in words is "one billion, nine hundred nineteen million, seven hundred seventy-nine thousand, nine hundred ninety".