19964397 has 8 divisors (see below), whose sum is σ = 26650944. Its totient is φ = 13293728.

The previous prime is 19964389. The next prime is 19964429. The reversal of 19964397 is 79346991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19964397 - 2³ = 19964389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19964317) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 633 + ... + 6350.

It is an arithmetic number, because the mean of its divisors is an integer number (3331368).

Almost surely, 2^19964397 is an apocalyptic number.

It is an amenable number.

19964397 is a deficient number, since it is larger than the sum of its proper divisors (6686547).

19964397 is an equidigital number, since it uses as much as digits as its factorization.

19964397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7939.

The product of its digits is 367416, while the sum is 48.

The square root of 19964397 is about 4468.1536455229. The cubic root of 19964397 is about 271.2805969718.

The spelling of 19964397 in words is "nineteen million, nine hundred sixty-four thousand, three hundred ninety-seven".