21352830 has 32 divisors (see below), whose sum is σ = 51521184. Its totient is φ = 5663616.

The previous prime is 21352801. The next prime is 21352843. The reversal of 21352830 is 3825312.

It is a self number, because there is not a number n which added to its sum of digits gives 21352830.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4104 + ... + 7716.

It is an arithmetic number, because the mean of its divisors is an integer number (1610037).

Almost surely, 2^21352830 is an apocalyptic number.

21352830 is an abundant number, since it is smaller than the sum of its proper divisors (30168354).

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

21352830 is a wasteful number, since it uses less digits than its factorization.

21352830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3820.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 21352830 is about 4620.9122475979. The cubic root of 21352830 is about 277.4289729753.

The spelling of 21352830 in words is "twenty-one million, three hundred fifty-two thousand, eight hundred thirty".