21400032 has 48 divisors (see below), whose sum is σ = 57555792. Its totient is φ = 6958080.

The previous prime is 21400031. The next prime is 21400037. The reversal of 21400032 is 23000412.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×21400032² = 915922739202048, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21399990 and 21400017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21400031) 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, 1218 + ... + 6654.

It is an arithmetic number, because the mean of its divisors is an integer number (1199079).

Almost surely, 2^21400032 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21400032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28777896).

21400032 is an abundant number, since it is smaller than the sum of its proper divisors (36155760).

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

21400032 is a wasteful number, since it uses less digits than its factorization.

21400032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5491 (or 5483 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 21400032 is about 4626.0168611885. The cubic root of 21400032 is about 277.6332482386.

Adding to 21400032 its reverse (23000412), we get a palindrome (44400444).

The spelling of 21400032 in words is "twenty-one million, four hundred thousand, thirty-two".