19724039 has 2 divisors, whose sum is σ = 19724040. Its totient is φ = 19724038.

The previous prime is 19724017. The next prime is 19724093. The reversal of 19724039 is 93042791.

Together with next prime (19724093) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19724039 - 2¹² = 19719943 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19724099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9862019 + 9862020.

It is an arithmetic number, because the mean of its divisors is an integer number (9862020).

Almost surely, 2^19724039 is an apocalyptic number.

19724039 is a deficient number, since it is larger than the sum of its proper divisors (1).

19724039 is an equidigital number, since it uses as much as digits as its factorization.

19724039 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 19724039 is about 4441.1754074794. The cubic root of 19724039 is about 270.1875194830.

The spelling of 19724039 in words is "nineteen million, seven hundred twenty-four thousand, thirty-nine".