19661949 has 12 divisors (see below), whose sum is σ = 28481596. Its totient is φ = 13070592.

The previous prime is 19661923. The next prime is 19661951. The reversal of 19661949 is 94916691.

It can be written as a sum of positive squares in 2 ways, for example, as 15327225 + 4334724 = 3915^2 + 2082^2 .

It is not a de Polignac number, because 19661949 - 2⁷ = 19661821 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 (19661909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 429 + ... + 6285.

Almost surely, 2^19661949 is an apocalyptic number.

It is an amenable number.

19661949 is a deficient number, since it is larger than the sum of its proper divisors (8819647).

19661949 is a wasteful number, since it uses less digits than its factorization.

19661949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6236 (or 6233 counting only the distinct ones).

The product of its digits is 104976, while the sum is 45.

The square root of 19661949 is about 4434.1796310028. The cubic root of 19661949 is about 269.9037105206.

The spelling of 19661949 in words is "nineteen million, six hundred sixty-one thousand, nine hundred forty-nine".