21429634 has 8 divisors (see below), whose sum is σ = 32928588. Its totient is φ = 10453440.

The previous prime is 21429613. The next prime is 21429641. The reversal of 21429634 is 43692412.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 16024009 + 5405625 = 4003^2 + 2325^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21429596 and 21429605.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 130587 + ... + 130750.

Almost surely, 2^21429634 is an apocalyptic number.

21429634 is a deficient number, since it is larger than the sum of its proper divisors (11498954).

21429634 is a wasteful number, since it uses less digits than its factorization.

21429634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261380.

The product of its digits is 10368, while the sum is 31.

The square root of 21429634 is about 4629.2152682717. The cubic root of 21429634 is about 277.7612030762.

The spelling of 21429634 in words is "twenty-one million, four hundred twenty-nine thousand, six hundred thirty-four".