19742087 has 4 divisors (see below), whose sum is σ = 19772616. Its totient is φ = 19711560.

The previous prime is 19742077. The next prime is 19742123. The reversal of 19742087 is 78024791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78024791 = 13 ⋅6001907.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19742087 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19742087.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19742017) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14273 + ... + 15594.

It is an arithmetic number, because the mean of its divisors is an integer number (4943154).

Almost surely, 2^19742087 is an apocalyptic number.

19742087 is a deficient number, since it is larger than the sum of its proper divisors (30529).

19742087 is an equidigital number, since it uses as much as digits as its factorization.

19742087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30528.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 19742087 is about 4443.2068374092. The cubic root of 19742087 is about 270.2699038564.

The spelling of 19742087 in words is "nineteen million, seven hundred forty-two thousand, eighty-seven".