19797440 has 56 divisors (see below), whose sum is σ = 50779680. Its totient is φ = 7308288.

The previous prime is 19797439. The next prime is 19797443. The reversal of 19797440 is 4479791.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19797443) 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, 1781 + ... + 6539.

It is an arithmetic number, because the mean of its divisors is an integer number (906780).

Almost surely, 2^19797440 is an apocalyptic number.

19797440 is a gapful number since it is divisible by the number (10) 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 19797440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25389840).

19797440 is an abundant number, since it is smaller than the sum of its proper divisors (30982240).

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

19797440 is a wasteful number, since it uses less digits than its factorization.

19797440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4789 (or 4779 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 41.

The square root of 19797440 is about 4449.4314243508. The cubic root of 19797440 is about 270.5222630225.

The spelling of 19797440 in words is "nineteen million, seven hundred ninety-seven thousand, four hundred forty".