21895040 has 32 divisors (see below), whose sum is σ = 52344360. Its totient is φ = 8757760.

The previous prime is 21895039. The next prime is 21895043. The reversal of 21895040 is 4059812.

It is a tau number, because it is divible by the number of its divisors (32).

It is a junction number, because it is equal to n+sod(n) for n = 21894994 and 21895012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21895043) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16466 + ... + 17745.

Almost surely, 2^21895040 is an apocalyptic number.

21895040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21895040 is an abundant number, since it is smaller than the sum of its proper divisors (30449320).

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

21895040 is an equidigital number, since it uses as much as digits as its factorization.

21895040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34230 (or 34218 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 21895040 is about 4679.2136091442. The cubic root of 21895040 is about 279.7576133638.

The spelling of 21895040 in words is "twenty-one million, eight hundred ninety-five thousand, forty".