19728623 has 2 divisors, whose sum is σ = 19728624. Its totient is φ = 19728622.

The previous prime is 19728607. The next prime is 19728629. The reversal of 19728623 is 32682791.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19728623 - 2⁴ = 19728607 is a prime.

It is a super-2 number, since 2×19728623² = 778437130952258, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19728629) 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, 9864311 + 9864312.

It is an arithmetic number, because the mean of its divisors is an integer number (9864312).

Almost surely, 2^19728623 is an apocalyptic number.

19728623 is a deficient number, since it is larger than the sum of its proper divisors (1).

19728623 is an equidigital number, since it uses as much as digits as its factorization.

19728623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 38.

The square root of 19728623 is about 4441.6914570915. The cubic root of 19728623 is about 270.2084489970.

It can be divided in two parts, 197286 and 23, that multiplied together give a triangular number (4537578 = T₃₀₁₂).

The spelling of 19728623 in words is "nineteen million, seven hundred twenty-eight thousand, six hundred twenty-three".