21428034 has 16 divisors (see below), whose sum is σ = 43257888. Its totient is φ = 7075712.

The previous prime is 21428021. The next prime is 21428051. The reversal of 21428034 is 43082412.

It is a super-2 number, since 2×21428034² = 918321282210312, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21427995 and 21428013.

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 7 ways as a sum of consecutive naturals, for example, 16047 + ... + 17330.

It is an arithmetic number, because the mean of its divisors is an integer number (2703618).

Almost surely, 2^21428034 is an apocalyptic number.

21428034 is an abundant number, since it is smaller than the sum of its proper divisors (21829854).

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

21428034 is a wasteful number, since it uses less digits than its factorization.

21428034 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33489.

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 21428034 is about 4629.0424495785. The cubic root of 21428034 is about 277.7542900792.

The spelling of 21428034 in words is "twenty-one million, four hundred twenty-eight thousand, thirty-four".