19946645 has 4 divisors (see below), whose sum is σ = 23935980. Its totient is φ = 15957312.

The previous prime is 19946629. The next prime is 19946651. The reversal of 19946645 is 54664991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54664991 = 127 ⋅430433.

It can be written as a sum of positive squares in 2 ways, for example, as 8427409 + 11519236 = 2903^2 + 3394^2 .

It is a cyclic number.

It is not a de Polignac number, because 19946645 - 2⁴ = 19946629 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 19946596 and 19946605.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1994660 + ... + 1994669.

It is an arithmetic number, because the mean of its divisors is an integer number (5983995).

Almost surely, 2^19946645 is an apocalyptic number.

It is an amenable number.

19946645 is a deficient number, since it is larger than the sum of its proper divisors (3989335).

19946645 is an equidigital number, since it uses as much as digits as its factorization.

19946645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3989334.

The product of its digits is 233280, while the sum is 44.

The square root of 19946645 is about 4466.1667008745. The cubic root of 19946645 is about 271.2001671074.

The spelling of 19946645 in words is "nineteen million, nine hundred forty-six thousand, six hundred forty-five".