19949540 has 36 divisors (see below), whose sum is σ = 45280116. Its totient is φ = 7339392.

The previous prime is 19949539. The next prime is 19949543. The reversal of 19949540 is 4594991.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 6801664 + 13147876 = 2608^2 + 3626^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19949543) 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, 71882 + ... + 72158.

It is an arithmetic number, because the mean of its divisors is an integer number (1257781).

Almost surely, 2^19949540 is an apocalyptic number.

19949540 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 19949540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22640058).

19949540 is an abundant number, since it is smaller than the sum of its proper divisors (25330576).

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

19949540 is a wasteful number, since it uses less digits than its factorization.

19949540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576 (or 297 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 41.

The square root of 19949540 is about 4466.4907925574. The cubic root of 19949540 is about 271.2132868828.

The spelling of 19949540 in words is "nineteen million, nine hundred forty-nine thousand, five hundred forty".