21429105 has 16 divisors (see below), whose sum is σ = 35214144. Its totient is φ = 11119680.

The previous prime is 21429103. The next prime is 21429113. The reversal of 21429105 is 50192412.

It is not a de Polignac number, because 21429105 - 2¹ = 21429103 is a prime.

It is a super-2 number, since 2×21429105² = 918413082202050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21429103) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18751 + ... + 19860.

It is an arithmetic number, because the mean of its divisors is an integer number (2200884).

Almost surely, 2^21429105 is an apocalyptic number.

It is an amenable number.

21429105 is a deficient number, since it is larger than the sum of its proper divisors (13785039).

21429105 is a wasteful number, since it uses less digits than its factorization.

21429105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38656.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 21429105 is about 4629.1581308052. The cubic root of 21429105 is about 277.7589175047.

The spelling of 21429105 in words is "twenty-one million, four hundred twenty-nine thousand, one hundred five".