21014405 has 16 divisors (see below), whose sum is σ = 25933824. Its totient is φ = 16339200.

The previous prime is 21014381. The next prime is 21014407. The reversal of 21014405 is 50441012.

It is a de Polignac number, because none of the positive numbers 2^k-21014405 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21014407) 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, 52205 + ... + 52605.

It is an arithmetic number, because the mean of its divisors is an integer number (1620864).

Almost surely, 2^21014405 is an apocalyptic number.

It is an amenable number.

21014405 is a deficient number, since it is larger than the sum of its proper divisors (4919419).

21014405 is a wasteful number, since it uses less digits than its factorization.

21014405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 676.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 21014405 is about 4584.1471398724. The cubic root of 21014405 is about 275.9554862399.

Adding to 21014405 its reverse (50441012), we get a palindrome (71455417).

The spelling of 21014405 in words is "twenty-one million, fourteen thousand, four hundred five".