21953428 has 48 divisors (see below), whose sum is σ = 45440640. Its totient is φ = 9086976.

The previous prime is 21953419. The next prime is 21953447. The reversal of 21953428 is 82435912.

It is a junction number, because it is equal to n+sod(n) for n = 21953393 and 21953402.

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, 160176 + ... + 160312.

It is an arithmetic number, because the mean of its divisors is an integer number (946680).

Almost surely, 2^21953428 is an apocalyptic number.

21953428 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21953428 is an abundant number, since it is smaller than the sum of its proper divisors (23487212).

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

21953428 is a wasteful number, since it uses less digits than its factorization.

21953428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304 (or 302 counting only the distinct ones).

The product of its digits is 17280, while the sum is 34.

The square root of 21953428 is about 4685.4485377603. The cubic root of 21953428 is about 280.0060712969.

The spelling of 21953428 in words is "twenty-one million, nine hundred fifty-three thousand, four hundred twenty-eight".