21032428 has 12 divisors (see below), whose sum is σ = 37801792. Its totient is φ = 10231920.

The previous prime is 21032399. The next prime is 21032437. The reversal of 21032428 is 82423012.

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21032399 and 21032408.

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, 70908 + ... + 71203.

Almost surely, 2^21032428 is an apocalyptic number.

It is an amenable number.

21032428 is a deficient number, since it is larger than the sum of its proper divisors (16769364).

21032428 is a wasteful number, since it uses less digits than its factorization.

21032428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142152 (or 142150 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 21032428 is about 4586.1125149739. The cubic root of 21032428 is about 276.0343547518.

The spelling of 21032428 in words is "twenty-one million, thirty-two thousand, four hundred twenty-eight".