19939993 has 2 divisors, whose sum is σ = 19939994. Its totient is φ = 19939992.

The previous prime is 19939973. The next prime is 19940017. The reversal of 19939993 is 39993991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12027024 + 7912969 = 3468^2 + 2813^2 .

It is a cyclic number.

It is not a de Polignac number, because 19939993 - 2⁵ = 19939961 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19939993.

It is not a weakly prime, because it can be changed into another prime (19939943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9969996 + 9969997.

It is an arithmetic number, because the mean of its divisors is an integer number (9969997).

Almost surely, 2^19939993 is an apocalyptic number.

It is an amenable number.

19939993 is a deficient number, since it is larger than the sum of its proper divisors (1).

19939993 is an equidigital number, since it uses as much as digits as its factorization.

19939993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 531441, while the sum is 52.

The square root of 19939993 is about 4465.4219285528. The cubic root of 19939993 is about 271.1700162711.

The spelling of 19939993 in words is "nineteen million, nine hundred thirty-nine thousand, nine hundred ninety-three".