19964805 has 48 divisors (see below), whose sum is σ = 38807424. Its totient is φ = 8722560.

The previous prime is 19964803. The next prime is 19964821. The reversal of 19964805 is 50846991.

It is not a de Polignac number, because 19964805 - 2¹ = 19964803 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19964803) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 16315 + ... + 17495.

It is an arithmetic number, because the mean of its divisors is an integer number (808488).

Almost surely, 2^19964805 is an apocalyptic number.

19964805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19964805 is a deficient number, since it is larger than the sum of its proper divisors (18842619).

19964805 is a wasteful number, since it uses less digits than its factorization.

19964805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1226 (or 1219 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 42.

The square root of 19964805 is about 4468.1993017322. The cubic root of 19964805 is about 271.2824449570.

The spelling of 19964805 in words is "nineteen million, nine hundred sixty-four thousand, eight hundred five".