21400332 has 12 divisors (see below), whose sum is σ = 49934136. Its totient is φ = 7133440.

The previous prime is 21400277. The next prime is 21400343. The reversal of 21400332 is 23300412.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 891669 + ... + 891692.

It is an arithmetic number, because the mean of its divisors is an integer number (4161178).

Almost surely, 2^21400332 is an apocalyptic number.

It is an amenable number.

21400332 is an abundant number, since it is smaller than the sum of its proper divisors (28533804).

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

21400332 is a wasteful number, since it uses less digits than its factorization.

21400332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1783368 (or 1783366 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 21400332 is about 4626.0492863782. The cubic root of 21400332 is about 277.6345455822.

Adding to 21400332 its reverse (23300412), we get a palindrome (44700744).

The spelling of 21400332 in words is "twenty-one million, four hundred thousand, three hundred thirty-two".