19697664 has 104 divisors (see below), whose sum is σ = 60285760. Its totient is φ = 5603328.

The previous prime is 19697659. The next prime is 19697669. The reversal of 19697664 is 46679691.

It is an interprime number because it is at equal distance from previous prime (19697659) and next prime (19697669).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (19697669) 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, 85902 + ... + 86130.

Almost surely, 2^19697664 is an apocalyptic number.

19697664 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19697664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30142880).

19697664 is an abundant number, since it is smaller than the sum of its proper divisors (40588096).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19697664 is an equidigital number, since it uses as much as digits as its factorization.

19697664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263 (or 241 counting only the distinct ones).

The product of its digits is 489888, while the sum is 48.

The square root of 19697664 is about 4438.2050425820. The cubic root of 19697664 is about 270.0670341102.

The spelling of 19697664 in words is "nineteen million, six hundred ninety-seven thousand, six hundred sixty-four".