21014864 has 40 divisors (see below), whose sum is σ = 44497152. Its totient is φ = 9555840.

The previous prime is 21014863. The next prime is 21014867. The reversal of 21014864 is 46841012.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21014863) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14057 + ... + 15479.

Almost surely, 2^21014864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21014864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22248576).

21014864 is an abundant number, since it is smaller than the sum of its proper divisors (23482288).

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

21014864 is a wasteful number, since it uses less digits than its factorization.

21014864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1515 (or 1509 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 21014864 is about 4584.1972034370. The cubic root of 21014864 is about 275.9574953799.

Adding to 21014864 its reverse (46841012), we get a palindrome (67855876).

The spelling of 21014864 in words is "twenty-one million, fourteen thousand, eight hundred sixty-four".