19778023 has 4 divisors (see below), whose sum is σ = 20198880. Its totient is φ = 19357168.

The previous prime is 19777991. The next prime is 19778027. The reversal of 19778023 is 32087791.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19778023 - 2⁵ = 19777991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19778027) 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, 210358 + ... + 210451.

It is an arithmetic number, because the mean of its divisors is an integer number (5049720).

Almost surely, 2^19778023 is an apocalyptic number.

19778023 is a deficient number, since it is larger than the sum of its proper divisors (420857).

19778023 is an equidigital number, since it uses as much as digits as its factorization.

19778023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420856.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 19778023 is about 4447.2489248973. The cubic root of 19778023 is about 270.4337928469.

It can be divided in two parts, 1977 and 8023, that added together give a 4-th power (10000 = 10⁴).

The spelling of 19778023 in words is "nineteen million, seven hundred seventy-eight thousand, twenty-three".