21968430 has 32 divisors (see below), whose sum is σ = 57518208. Its totient is φ = 5325600.

The previous prime is 21968413. The next prime is 21968431. The reversal of 21968430 is 3486912.

It is a super-2 number, since 2×21968430² = 965223833329800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21968391 and 21968400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21968431) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32956 + ... + 33615.

It is an arithmetic number, because the mean of its divisors is an integer number (1797444).

Almost surely, 2^21968430 is an apocalyptic number.

21968430 is an abundant number, since it is smaller than the sum of its proper divisors (35549778).

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

21968430 is a wasteful number, since it uses less digits than its factorization.

21968430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66592.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 21968430 is about 4687.0491783210. The cubic root of 21968430 is about 280.0698380216.

The spelling of 21968430 in words is "twenty-one million, nine hundred sixty-eight thousand, four hundred thirty".