21478014 has 64 divisors (see below), whose sum is σ = 49896000. Its totient is φ = 6842880.

The previous prime is 21478007. The next prime is 21478049. The reversal of 21478014 is 41087412.

It is a super-2 number, since 2×21478014² = 922610170768392, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 196992 + ... + 197100.

It is an arithmetic number, because the mean of its divisors is an integer number (779625).

Almost surely, 2^21478014 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21478014, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24948000).

21478014 is an abundant number, since it is smaller than the sum of its proper divisors (28417986).

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

21478014 is a wasteful number, since it uses less digits than its factorization.

21478014 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250 (or 244 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 21478014 is about 4634.4378299854. The cubic root of 21478014 is about 277.9700725163.

The spelling of 21478014 in words is "twenty-one million, four hundred seventy-eight thousand, fourteen".