19743949 has 2 divisors, whose sum is σ = 19743950. Its totient is φ = 19743948.

The previous prime is 19743929. The next prime is 19743989. The reversal of 19743949 is 94934791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18966025 + 777924 = 4355^2 + 882^2 .

It is a cyclic number.

It is not a de Polignac number, because 19743949 - 2¹⁷ = 19612877 is a prime.

It is a super-2 number, since 2×19743949² = 779647044229202, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 19743899 and 19743908.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19743929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9871974 + 9871975.

It is an arithmetic number, because the mean of its divisors is an integer number (9871975).

Almost surely, 2^19743949 is an apocalyptic number.

It is an amenable number.

19743949 is a deficient number, since it is larger than the sum of its proper divisors (1).

19743949 is an equidigital number, since it uses as much as digits as its factorization.

19743949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 244944, while the sum is 46.

The square root of 19743949 is about 4443.4163658158. The cubic root of 19743949 is about 270.2784005389.

It can be divided in two parts, 1974 and 3949, that multiplied together give a triangular number (7795326 = T₃₉₄₈).

The spelling of 19743949 in words is "nineteen million, seven hundred forty-three thousand, nine hundred forty-nine".