21429530 has 16 divisors (see below), whose sum is σ = 40603680. Its totient is φ = 8120592.

The previous prime is 21429451. The next prime is 21429533. The reversal of 21429530 is 3592412.

It is a self number, because there is not a number n which added to its sum of digits gives 21429530.

It is not an unprimeable number, because it can be changed into a prime (21429533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56204 + ... + 56583.

It is an arithmetic number, because the mean of its divisors is an integer number (2537730).

Almost surely, 2^21429530 is an apocalyptic number.

21429530 is a deficient number, since it is larger than the sum of its proper divisors (19174150).

21429530 is a wasteful number, since it uses less digits than its factorization.

21429530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112813.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 21429530 is about 4629.2040352527. The cubic root of 21429530 is about 277.7607537419.

The spelling of 21429530 in words is "twenty-one million, four hundred twenty-nine thousand, five hundred thirty".