19877993 has 4 divisors (see below), whose sum is σ = 19935300. Its totient is φ = 19820688.

The previous prime is 19877987. The next prime is 19878007. The reversal of 19877993 is 39977891.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7823209 + 12054784 = 2797^2 + 3472^2 .

It is a cyclic number.

It is not a de Polignac number, because 19877993 - 2¹⁴ = 19861609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19877903) 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, 28130 + ... + 28827.

It is an arithmetic number, because the mean of its divisors is an integer number (4983825).

Almost surely, 2^19877993 is an apocalyptic number.

It is an amenable number.

19877993 is a deficient number, since it is larger than the sum of its proper divisors (57307).

19877993 is an equidigital number, since it uses as much as digits as its factorization.

19877993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57306.

The product of its digits is 857304, while the sum is 53.

The square root of 19877993 is about 4458.4742906066. The cubic root of 19877993 is about 270.8886722002. Note that the first 3 decimals are identical.

The spelling of 19877993 in words is "nineteen million, eight hundred seventy-seven thousand, nine hundred ninety-three".