21261432 has 16 divisors (see below), whose sum is σ = 53153640. Its totient is φ = 7087136.

The previous prime is 21261413. The next prime is 21261433. The reversal of 21261432 is 23416212.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21261399 and 21261408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21261433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 442923 + ... + 442970.

Almost surely, 2^21261432 is an apocalyptic number.

It is an amenable number.

21261432 is an abundant number, since it is smaller than the sum of its proper divisors (31892208).

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

21261432 is a wasteful number, since it uses less digits than its factorization.

21261432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 885902 (or 885898 counting only the distinct ones).

The product of its digits is 576, while the sum is 21.

The square root of 21261432 is about 4611.0120364189. The cubic root of 21261432 is about 277.0325740299.

Adding to 21261432 its reverse (23416212), we get a palindrome (44677644).

The spelling of 21261432 in words is "twenty-one million, two hundred sixty-one thousand, four hundred thirty-two".