19660421 has 12 divisors (see below), whose sum is σ = 22640544. Its totient is φ = 16929000.

The previous prime is 19660411. The next prime is 19660441. The reversal of 19660421 is 12406691.

It is a de Polignac number, because none of the positive numbers 2^k-19660421 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 (19660411) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1496 + ... + 6446.

It is an arithmetic number, because the mean of its divisors is an integer number (1886712).

Almost surely, 2^19660421 is an apocalyptic number.

19660421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

19660421 is a deficient number, since it is larger than the sum of its proper divisors (2980123).

19660421 is a wasteful number, since it uses less digits than its factorization.

19660421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5000 (or 4981 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 19660421 is about 4434.0073297188. The cubic root of 19660421 is about 269.8967186136.

The spelling of 19660421 in words is "nineteen million, six hundred sixty thousand, four hundred twenty-one".