19780730 has 16 divisors (see below), whose sum is σ = 35656200. Its totient is φ = 7900992.

The previous prime is 19780727. The next prime is 19780751. The reversal of 19780730 is 3708791.

It can be written as a sum of positive squares in 4 ways, for example, as 15784729 + 3996001 = 3973^2 + 1999^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11996 + ... + 13544.

Almost surely, 2^19780730 is an apocalyptic number.

19780730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19780730 is a deficient number, since it is larger than the sum of its proper divisors (15875470).

19780730 is a wasteful number, since it uses less digits than its factorization.

19780730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2833.

The product of its (nonzero) digits is 10584, while the sum is 35.

The square root of 19780730 is about 4447.5532599397. The cubic root of 19780730 is about 270.4461302931.

The spelling of 19780730 in words is "nineteen million, seven hundred eighty thousand, seven hundred thirty".