21029004 has 24 divisors (see below), whose sum is σ = 54519920. Its totient is φ = 7009632.

The previous prime is 21029003. The next prime is 21029033. The reversal of 21029004 is 40092012.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21029003) 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, 97249 + ... + 97464.

Almost surely, 2^21029004 is an apocalyptic number.

It is an amenable number.

21029004 is an abundant number, since it is smaller than the sum of its proper divisors (33490916).

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

21029004 is a wasteful number, since it uses less digits than its factorization.

21029004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194726 (or 194718 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 21029004 is about 4585.7391988642. The cubic root of 21029004 is about 276.0193748214.

The spelling of 21029004 in words is "twenty-one million, twenty-nine thousand, four".