19781072 has 10 divisors (see below), whose sum is σ = 38325858. Its totient is φ = 9890528.

The previous prime is 19781053. The next prime is 19781077. The reversal of 19781072 is 27018791.

It can be written as a sum of positive squares in only one way, i.e., 11806096 + 7974976 = 3436^2 + 2824^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19781077) 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 as a sum of consecutive naturals, namely, 618143 + ... + 618174.

Almost surely, 2^19781072 is an apocalyptic number.

It is an amenable number.

19781072 is a deficient number, since it is larger than the sum of its proper divisors (18544786).

19781072 is a wasteful number, since it uses less digits than its factorization.

19781072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1236325 (or 1236319 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 35.

The square root of 19781072 is about 4447.5917078797. The cubic root of 19781072 is about 270.4476889151.

The spelling of 19781072 in words is "nineteen million, seven hundred eighty-one thousand, seventy-two".