21437732 has 6 divisors (see below), whose sum is σ = 37516038. Its totient is φ = 10718864.

The previous prime is 21437723. The next prime is 21437747. The reversal of 21437732 is 23773412.

It can be written as a sum of positive squares in only one way, i.e., 19571776 + 1865956 = 4424^2 + 1366^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21437695 and 21437704.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2679713 + ... + 2679720.

It is an arithmetic number, because the mean of its divisors is an integer number (6252673).

Almost surely, 2^21437732 is an apocalyptic number.

It is an amenable number.

21437732 is a deficient number, since it is larger than the sum of its proper divisors (16078306).

21437732 is a wasteful number, since it uses less digits than its factorization.

21437732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5359437 (or 5359435 counting only the distinct ones).

The product of its digits is 7056, while the sum is 29.

The square root of 21437732 is about 4630.0898479403. The cubic root of 21437732 is about 277.7961862052.

The spelling of 21437732 in words is "twenty-one million, four hundred thirty-seven thousand, seven hundred thirty-two".