19499661 has 6 divisors (see below), whose sum is σ = 28166190. Its totient is φ = 12999768.

The previous prime is 19499657. The next prime is 19499671. The reversal of 19499661 is 16699491.

It can be written as a sum of positive squares in only one way, i.e., 16281225 + 3218436 = 4035^2 + 1794^2 .

It is not a de Polignac number, because 19499661 - 2² = 19499657 is a prime.

It is a super-2 number, since 2×19499661² = 760473558229842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19499671) 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 5 ways as a sum of consecutive naturals, for example, 1083306 + ... + 1083323.

It is an arithmetic number, because the mean of its divisors is an integer number (4694365).

Almost surely, 2^19499661 is an apocalyptic number.

It is an amenable number.

19499661 is a deficient number, since it is larger than the sum of its proper divisors (8666529).

19499661 is a wasteful number, since it uses less digits than its factorization.

19499661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2166635 (or 2166632 counting only the distinct ones).

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

The square root of 19499661 is about 4415.8420488056. The cubic root of 19499661 is about 269.1590708440.

The spelling of 19499661 in words is "nineteen million, four hundred ninety-nine thousand, six hundred sixty-one".