19940040 has 128 divisors (see below), whose sum is σ = 68400000. Its totient is φ = 5163264.

The previous prime is 19940033. The next prime is 19940047. The reversal of 19940040 is 4004991.

It is an interprime number because it is at equal distance from previous prime (19940033) and next prime (19940047).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 19939986 and 19940013.

It is not an unprimeable number, because it can be changed into a prime (19940047) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39711 + ... + 40209.

It is an arithmetic number, because the mean of its divisors is an integer number (534375).

Almost surely, 2^19940040 is an apocalyptic number.

19940040 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 19940040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34200000).

19940040 is an abundant number, since it is smaller than the sum of its proper divisors (48459960).

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

19940040 is a wasteful number, since it uses less digits than its factorization.

19940040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 556 (or 546 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 19940040 is about 4465.4271912103. The cubic root of 19940040 is about 271.1702293266.

The spelling of 19940040 in words is "nineteen million, nine hundred forty thousand, forty".