19953945 has 48 divisors (see below), whose sum is σ = 39154752. Its totient is φ = 9668160.

The previous prime is 19953919. The next prime is 19953953. The reversal of 19953945 is 54935991.

It is a happy number.

It is not a de Polignac number, because 19953945 - 2¹⁰ = 19952921 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 19953945.

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 47 ways as a sum of consecutive naturals, for example, 12619 + ... + 14111.

It is an arithmetic number, because the mean of its divisors is an integer number (815724).

Almost surely, 2^19953945 is an apocalyptic number.

19953945 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19953945 is a deficient number, since it is larger than the sum of its proper divisors (19200807).

19953945 is a wasteful number, since it uses less digits than its factorization.

19953945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1524 (or 1512 counting only the distinct ones).

The product of its digits is 218700, while the sum is 45.

The square root of 19953945 is about 4466.9838817708. The cubic root of 19953945 is about 271.2332473532.

The spelling of 19953945 in words is "nineteen million, nine hundred fifty-three thousand, nine hundred forty-five".