19779742 has 16 divisors (see below), whose sum is σ = 30615552. Its totient is φ = 9578520.

The previous prime is 19779713. The next prime is 19779743. The reversal of 19779742 is 24797791.

It is a junction number, because it is equal to n+sod(n) for n = 19779692 and 19779701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19779743) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 10017 + ... + 11827.

It is an arithmetic number, because the mean of its divisors is an integer number (1913472).

Almost surely, 2^19779742 is an apocalyptic number.

19779742 is a deficient number, since it is larger than the sum of its proper divisors (10835810).

19779742 is a wasteful number, since it uses less digits than its factorization.

19779742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1983.

The product of its digits is 222264, while the sum is 46.

The square root of 19779742 is about 4447.4421862459. The cubic root of 19779742 is about 270.4416275063.

The spelling of 19779742 in words is "nineteen million, seven hundred seventy-nine thousand, seven hundred forty-two".