21719040 has 192 divisors, whose sum is σ = 80196480. Its totient is φ = 4915200.

The previous prime is 21719023. The next prime is 21719041. The reversal of 21719040 is 4091712.

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 21719040.

It is not an unprimeable number, because it can be changed into a prime (21719041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 214990 + ... + 215090.

It is an arithmetic number, because the mean of its divisors is an integer number (417690).

Almost surely, 2^21719040 is an apocalyptic number.

21719040 is a gapful number since it is divisible by the number (20) 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 21719040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40098240).

21719040 is an abundant number, since it is smaller than the sum of its proper divisors (58477440).

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

21719040 is a wasteful number, since it uses less digits than its factorization.

21719040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 21719040 is about 4660.3690840962. The cubic root of 21719040 is about 279.0059992800.

It can be divided in two parts, 2171 and 9040, that added together give a palindrome (11211).

The spelling of 21719040 in words is "twenty-one million, seven hundred nineteen thousand, forty".