19664949 has 4 divisors (see below), whose sum is σ = 26219936. Its totient is φ = 13109964.

The previous prime is 19664947. The next prime is 19664951. The reversal of 19664949 is 94946691.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (19664947) and next prime (19664951).

It is not a de Polignac number, because 19664949 - 2¹ = 19664947 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19664898 and 19664907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19664947) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3277489 + ... + 3277494.

It is an arithmetic number, because the mean of its divisors is an integer number (6554984).

Almost surely, 2^19664949 is an apocalyptic number.

It is an amenable number.

19664949 is a deficient number, since it is larger than the sum of its proper divisors (6554987).

19664949 is an equidigital number, since it uses as much as digits as its factorization.

19664949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6554986.

The product of its digits is 419904, while the sum is 48.

The square root of 19664949 is about 4434.5178993888. The cubic root of 19664949 is about 269.9174370328.

The spelling of 19664949 in words is "nineteen million, six hundred sixty-four thousand, nine hundred forty-nine".