21428526 has 16 divisors (see below), whose sum is σ = 48979584. Its totient is φ = 6122424.

The previous prime is 21428509. The next prime is 21428531. The reversal of 21428526 is 62582412.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21428493 and 21428502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 255060 + ... + 255143.

It is an arithmetic number, because the mean of its divisors is an integer number (3061224).

Almost surely, 2^21428526 is an apocalyptic number.

21428526 is an abundant number, since it is smaller than the sum of its proper divisors (27551058).

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

21428526 is a wasteful number, since it uses less digits than its factorization.

21428526 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510215.

The product of its digits is 7680, while the sum is 30.

The square root of 21428526 is about 4629.0955920136. The cubic root of 21428526 is about 277.7564158624.

The spelling of 21428526 in words is "twenty-one million, four hundred twenty-eight thousand, five hundred twenty-six".